Color Difference Research Articles

Improved You Only Look Once v.8 Model Based on Deep Learning: Precision Detection and Recognition of Fresh Leaves from Yunnan Large-Leaf Tea Tree

Yunnan Province, China, known for its superior ecological environment and diverse climate conditions, is home to a rich resource of tea-plant varieties. However, the subtle differences in shape, color and size among the fresh leaves of different tea-plant varieties pose significant challenges for their identification and detection. This study proposes an improved YOLOv8 model based on a dataset of fresh leaves from five tea-plant varieties among Yunnan large-leaf tea trees. Dynamic Upsampling replaces the UpSample module in the original YOLOv8, reducing the data volume in the training process. The Efficient Pyramid Squeeze Attention Network is integrated into the backbone of the YOLOv8 network to boost the network’s capability to handle multi-scale spatial information. To improve model performance and reduce the number of redundant features within the network, a Spatial and Channel Reconstruction Convolution module is introduced. Lastly, Inner-SIoU is adopted to reduce network loss and accelerate the convergence of regression. Experimental results indicate that the improved YOLOv8 model achieves precision, recall and an mAP of 88.4%, 89.9% and 94.8%, representing improvements of 7.1%, 3.9% and 3.4% over the original model. This study’s proposed improved YOLOv8 model not only identifies fresh leaves from different tea-plant varieties but also achieves graded recognition, effectively addressing the issues of strong subjectivity in manual identification detection, the long training time of the traditional deep learning model and high hardware cost. It establishes a robust technical foundation for the intelligent and refined harvesting of tea in Yunnan’s tea gardens.

Color Masking Ability of Guided Enamel Regeneration with a Novel Self-Assembling Peptide and Resin Infiltration on Artificial Enamel Lesions Under Various Challenges: An In Vitro Spectrophotometric Analysis

The color masking ability of resin infiltration (RI) and curodont repair fluoride plus–self-assembling peptide (CRFP-SAP) was investigated under various simulated oral challenging conditions. Sixty-four extracted caries-free human canines were randomly divided into two groups: Group 1 (RI) and Group 2 (CRFP-SAP). The baseline color values of samples were recorded using a spectrophotometer (VITA Easyshade® Advance 4.0 VITA Zahnfabrik, Bad Sackingen, Germany). The samples were stored in a demineralization solution for 4 days to induce artificial enamel lesions (AELs). The AELs of Groups I and II were treated with RI (Icon, DMG, Hamburg, Germany) and CRFP-SAP (vVARDIS, Zug, Switzerland), respectively, followed by color measurements. Each group was subjected to challenges such as remineralization, pH cycling, staining, and thermocycling, followed by color measurements. The difference between the mean ∆E (color difference value) of sound enamel and both treatment groups was less than 3.7 1-week post treatment. Meanwhile, the difference between the mean ∆E of RI-treated samples and all kinds of challenges was more than 3.7, while for the CRFP-SAP-treated samples, it was less than 3.7 for all kinds of challenges, except for the thermocycling, for which the mean ∆E difference was 4.3. RI and CRFP-SAP treatments were effective in masking the discoloration caused by AELs. However, the color was not stable for RI-treated samples, whereas it was stable for CRFP-SAP-treated samples under all challenges, except for thermocycling.

Study on the Effects of Ginger Extract on the Degree of Hydrolysis, Sensory Evaluation, Color Difference, and Volatile Flavor Components of Oyster Enzymatic Hydrolysate

Study on the Effects of Ginger Extract on the Degree of Hydrolysis, Sensory Evaluation, Color Difference, and Volatile Flavor Components of Oyster Enzymatic Hydrolysate

The occurrences, characteristics, and implications of chaotic rocks (accretionary rocks) within the Trans-Saharan orogenic belt in Nigeria

The present research paper reveals the occurrences of metachaotic rocks/accretionary sediments (mélange) in Igarra, southwest Nigeria. These metachaotic rocks are associated with schistose, marble, pegmatite, granitoid, and gneissose units. The mineral assemblage of the surrounding rocks shows garnet, biotite, staurolite, quartz, and chlorite assemblage, which suggest that the rocks were metamorphosed to the epidote–amphibolite facies grade. The chaotic rocks were classified into four groups based on major differences in color, grain size distribution, and stratigraphic and structural characteristics of observed blocks and matrices surrounding them. Group I metachaotic rocks are melanocratic in color, and form pockets of coarse lineation. They are highly deformed with mullions, rodding structures, and burrow-like cavities and show quartzite veins. Group II occurs as a leucocratic to melanocratic mixture of meta-siltstone and metapelite with greenish rock fragments trapped within the meta-siltstone layers. This unit has a cover of meta-siltstone layers occurring in pockets as striations forming mullion and rodding structures as well as ripple-like lineation. Group III metachaotic rocks occur as multiple benches of different strata tilted between 70 and 80º, with mild folding and burrow-like cavities at the base and well-preserved sedimentary structures. In Group IV, there are evidences of pre-metamorphic soft sediment deformational structures that are well-preserved in the metachaotic rocks, with discontinuous blocks of different units trapped within mixtures of metapelite and meta-siltstone. In this group, micro-faults and quartzite veins are scattered within the rocks. Meta-siltstone occurs as horizontal and vertical layers and web-like structures showing dendritic patterns. Overall, the field and petrographic characteristics suggest the Igarra metachaotic rocks are tectonic in origin and may have been formed within the trench basin of an outer accretionary complex.

Color Assessment of Screw-Retained Implant Prostheses Access Hole Fillings: An In-Vitro Study

Objectives: This study aimed to investigate the aesthetic aspect of screw-retained restorations by examining three different types of filling materials used for the access cavity, highlighting the significance of aesthetics in implant restorations. Materials and Methods: In this laboratory investigation, simulation samples of screw-retained restorations were filled with flowable composite resin (group F), opaque and flowable composite resin (group O) and porcelain plug (group P) at baseline (T0). The samples were subjected to thermocycling twice (T1 and T3), undergoing 1000 cycles in coffee, orange juice, and distilled water, followed by washing performed after each thermocycling (T2 and T4). Colorimetric analysis and surface roughness measurements were conducted, and the data were statistically analyzed using. two-way analysis of variance (ANOVA), ,Tukey post hoc, two-way analysis of covariance (ANCOVA), and paired-t test. P<0.05 was considered significant. Results: The type of filling material had a significant effect on the color difference observed between the restoration and filling materials (P<0.05). Notably, samples from group P exhibited a more pronounced color difference at T4, despite showing a lower color difference at T0, when compared to group O. Conclusion: The use of porcelain plugs did not provide a notable advantage over the combination of flowable and opaque composite resins, particularly given the difficulties in fabricating and positioning porcelain plugs within the access cavity. Therefore, it is recommended to utilize flowable composite resins in conjunction with an opaque composite resin layer beneath, to effectively conceal any dark shades from the underlying metal.

Study on the Surface Properties of Lavender Microcapsule Fragrance-Releasing Flooring

This study investigates the effect of incorporating lavender microcapsules into flooring coatings on the surface properties of the flooring. The experimental results indicate that after adding lavender microcapsules, the flooring’s color, gloss, wear resistance, and hydrophobicity experienced slight changes, with a color difference (ΔE) below 2 units, gloss decreasing by 8%, and wear resistance reducing by approximately 5%. However, these changes were within an acceptable range. Chemical composition analysis confirmed the fragrance-releasing effect of the lavender microcapsules. Furthermore, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) verified the structural integrity of the microcapsules and their effective fragrance release. This study demonstrates that the introduction of lavender microcapsules not only enhances the scent perception of the flooring but also achieves long-term fragrance release while maintaining its fundamental physical properties, highlighting its potential for practical applications.

Spectrophotometric and calculative determination methods of textile color-difference threshold considering the observing condition

Purpose This study aims to investigate the varying color-difference thresholds for textiles under various illuminants. Design/methodology/approach To determine color-difference thresholds, 108 fabric samples with widely ranging colors were spectrophotometrically measured and visually assessed under four illumination conditions (correlated color temperatures of 2,856 K and 6,504 K; illuminances of 100 lx and 2,000 lx). Findings The mean spectrophotometric color-difference threshold (solely based on the textile’s physical color attributes in machine vision) was 4.22 ΔE*ab; thus, a mechanically measured color difference between two textiles (regardless of illuminant) of less than 4.22 ΔE*ab indicated individuals’ inability to differentiate between two textiles. The calculated color-difference thresholds, which reflected the color differences perceived by people considering textiles’ physical color attributes and the environmental factors in which they were observed, were higher than the spectrophotometric thresholds. This meant that under various illuminants, people had greater difficulty perceiving color differences than mechanically measured spectrophotometric thresholds. Particularly, larger discrepancies between the two threshold types occurred under reddish illuminants of 2,856 K than under bluish-white illuminants of 6,504 K. Furthermore, the extent to which people perceived color differences as distinct from actual differences under illumination was larger for greenish-blue textiles than for textiles of other hues. Originality/value The determined spectrophotometric and calculative color-difference thresholds for textiles can help fashion companies predict consumers’ perceptions of the colors of their textile products under various illuminants and, accordingly, appropriately plan colors of products and create standards for color quality control.

Selection of Grape Varieties for Canned Processing Based on Peeling Performance, Sensory Quality, and Storage Stability

The integration of grapes into canned food processing not only effectively extends their shelf life but also preserves their rich nutrition and delightful flavor. This marks a significant advancement toward value-added products and sustainability in the grape industry. This study aims to evaluate the appropriateness of different grape varieties for canned grape production, with a focus on peeling characteristics, sensory quality, and storage properties. Our findings reveal that Kyoho, Takatsuma, and Zuijinxiang grapes stand out as promising candidates, characterized by their ease of peeling, minimal peeling loss, and efficient peeling time. Subsequently, a fuzzy mathematical sensory evaluation approach was employed to assess the taste, flavor, texture, appearance, and size of the peeled grapes from nine grape varieties. Notably, Kyoho (3.87), Takatsuma (3.70), and Zuijinxiang (3.57) grapes exhibited superior sensory scores compared with the other varieties. Regarding storage quality, after 180 days of storage, Kyoho grapes exhibited lower color difference by 12.97–23.50%, higher brittleness by 13.77–19.17%, total phenolic content by 15.73–29.29%, total flavonoid content by 28.54–39.31%, anthocyanin content by 23.81–35.66%, and stronger antioxidant capacity (IC50 DPPH: 24.42–69.55%; IC50 ABTS: 13.27–57.43%) compared with Takatsuma and Zuijinxiang grapes. This comprehensive assessment highlights Kyoho grapes as the most suitable variety for canned grape production, followed by Takatsuma and Zuijinxiang grapes. Their exceptional peeling characteristics, sensory qualities, and notable storage resilience position them as promising candidates for commercialization, presenting substantial potential for widespread acceptance among consumers.

Underwater image enhancement based on optimally weighted histogram framework and improved Fick’s law algorithm

The quality of underwater images is often affected by light scattering and attenuation, resulting in a loss of contrast and brightness. To address this issue, this paper proposes an underwater image enhancement method: improved Fick’s law algorithm-based optimally weighted histogram framework (IFLAHF). The method incorporates the bi-histogram equalization-based three plateau limits (BHE3PL) technique to enhance image contrast and details while maintaining brightness. However, its dependence on fixed parameters limits its adaptability. To overcome this limitation, the paper introduces Fick’s law algorithm (FLA) and then improves it to optimize the fixed parameters. FLA is improved by incorporating Tent chaotic mapping and reverse learning to increase population diversity, and Levy flight is introduced in the later stages to enhance exploitation. Additionally, a color correction technique is applied to correct color deviations in underwater images, leading to a more natural appearance. To verify the performance of the method, it is compared with different methods. As demonstrated by simulations, the proposed method outperforms existing algorithms in multiple underwater image enhancement metrics.

Optimizing Aesthetic Appearance of Perovskite Solar Cells Using Color Filters

The significance of color aesthetics in photovoltaic (PV) modules gains importance, especially in design‐centric applications like building‐integrated PVs. Color filters based on distributed Bragg reflectors, consisting of alternating thin‐film layers of different refractive indices, can modify the appearance of standard silicon modules. This approach is also extended to optimize the color appearance of emerging PV technologies such as perovskite solar cells, which typically exhibit a less appealing gray–brownish appearance. In this contribution, perovskite solar‐cell stacks combined with MorphoColor color filters are presented. Angular‐resolved reflectance simulations based on wave optics and ray tracing with experimental data are validated, and the color appearance from various viewing angles is evaluated. Additionally, the impact of individual layers on color appearance and the maximum achievable short‐circuit current density in the perovskite solar cell is investigated. By applying Bayesian optimization, the color distance is minimized to the targeted appearance. Tailoring the bridging layers between the color filter and the perovskite solar cell is found to strongly influence the color impression due to the coherently combined color filter and perovskite solar cell. The presented color optimization concept allows to customize the aesthetics of emerging PV thin‐film technologies such as perovskite solar cells.

Prediction of the thermal degradation–induced colour change of acrylonitrile butadiene styrene products as a function of temperature and titanium dioxide content

In this study, we examined the thermal degradation–induced colour change of acrylonitrile butadiene styrene (ABS)–based titanium dioxide (TiO2)–doped products as a function of TiO2 content and temperature. Based on the time–temperature superposition (tTS) principle and the CIELAB colour space, we proposed a methodology for developing a robust model to estimate the long-term colour change of polymers doped with TiO2 at elevated temperatures. We used 800 h of measurement data to develop the model and validated the colour change predictions of the model in 1600 h. The average colour difference between the measured and modelled results at the application temperature range (below 80 °C) was <1.5, smaller than the just noticeable difference (JND) in the CIELAB colour space. We found that above a certain TiO2 content (approximately 3 wt%), the colour retention of the ABS/TiO2 specimens can no longer be improved by increasing their TiO2 content. To show the applicability of the model, we present two simple case studies predicting the colour and appearance of a polymer product under constant and variable heat loads. The proposed methodology provides an excellent tool for design, as it can be used to determine the optimum amount of TiO2. Moreover, it accelerates and simplifies the design process.

Feature Weighted Cycle Generative Adversarial Network with Facial Landmark Recognition and Perceptual Color Distance for Enhanced Face Animation Generation

We propose an anime style transfer model to generate anime faces from human face images. We improve the model by modifying the normalization function to obtain more feature information. To make the face feature position of the anime face similar to the human face, we propose facial landmark loss to calculate the error between the generated image and the real human face image. To avoid obvious color deviation in the generated images, we introduced perceptual color loss into the loss function. In addition, due to the lack of reasonable metrics to evaluate the quality of the animated images, we propose the use of Fréchet anime inception distance to calculate the distance between the distribution of the generated animated images and the real animated images in high-dimensional space, so as to understand the quality of the generated animated images. In the user survey, up to 74.46% of users think that the image produced by the proposed method is the best compared with other models. Also, the proposed method reaches a score of 126.05 for Fréchet anime inception distance. Our model performs the best in both user studies and FAID, showing that we have achieved better performance in human visual perception and model distribution. According to the experimental results and user feedback, our proposed method can generate results with better quality compared to existing methods.

A New Bivalve Species Glauconome huangheensis of the Genus Glauconome J. E. Gray, 1828 (Bivalvia, Venerida, Cyrenoidea, Glauconomidae), from Shandong, China

The family Glauconomidae has few species, limited molecular data description, and insufficient research attention. The biodiversity of Glauconomidae within China deserves further exploration. In recent years, the taxonomic status of Glauconomidae has undergone changes, and some studies have found a close relationship between Glauconomidae and the family Cyrenidae based on molecular data, suggesting that Glauconomidae should be classified under the superfamily Cyrenoidea. However, both domestic and international research has mainly focused on only four species of Glauconomidae, indicating an urgent need for more species data support. Recently, 46 specimens of Glauconomidae were collected in the Yellow River Estuary in Dongying City of Shandong Province in China. Through a comparative analysis of shell morphology and molecular phylogenetic analysis of COI and 16S rRNA, two species of Glauconomidae was discovered. One is Glauconome angulata Reeve, 1844, and the other is a new species of Glauconomidae found in the Yellow River, named Glauconome huangheensis sp. nov. The G. huangheensis sp. nov. exhibits distinct differences in shell shape and shell color compared to other species of Glauconomidae, resembling G. angulata. There are also significant differences in shell color, shell sculpture, ligament size, and shell thickness. Furthermore, the molecular phylogenetic analysis based on COI and 16S rRNA genes supports the validity of G. huangheensis sp. nov. as a species. It indicates a close phylogenetic relationship with G. angulata, making them sister species. This study provides a redescription of the morphological characteristics of G. angulata and G. huangheensis sp. nov., laying the foundation for the morphological classification, biodiversity research, and conservation of Glauconomidae species.

Comparison of different drying technologies for green tea: Changes in color, non-volatile and volatile compounds

Drying technology plays a pivotal role in tea processing. Herein, the differences in color, non-volatile, and volatile components of green tea under various drying methods were investigated. The results indicated that vacuum freeze-microwave increased the L* and b* values, and decreased the a* values of tea leaves. Moreover, vacuum freeze-microwave drying resulted in higher polyphenol content than the other three drying methods although there was no significant difference. A total of 43 volatile compounds were identified. Of these, 2-propanone, ethanol(D), ethanol(M), ethyl acetate(M), 2-methyl-1-butanol, and 2-methylthiophene were found to play an important role in the above discrimination (VIP >1.5). Dry extraction showed a higher content of volatile components than wet extraction. Regardless of the extraction conditions, vacuum freeze-microwave drying exhibited a stronger signal intensity and more volatile components than other drying methods. This study provides a reference for analyzing the quality differences of green tea by different drying methods.

Comprehensive Analysis of Geographical Impact on Flavor Profiles of Braised Chicken Across Eastern, Central, and Western China Using GC-IMS, E-Nose Techniques and Sensory Evaluation

The geographical influence on the flavor profiles and color differences of Braised Chicken from Eastern, Central, and Western China was investigated using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), electronic nose (E-nose) analysis, color-measuring instruments and sensory evaluation. To ensure the reproducibility and reliability, five types of braised chicken varieties were collected for five batches across six months. The model of E-nose PCA can effectively distinguish the five braised chicken samples. The five types of braised chicken showed distinct color differences. A total of 54 volatile compounds were identified by HS-GC-IMS, including 18 aldehydes,14 alcohols,10 ketones,5 esters,1 acid,1 furan, and 5 terpenes. The PLS-DA analysis revealed that the flavor of Daokou Braised Chicken (DZ) was significantly associated with aldehydes and ketones, Jingning Braised Chicken (JN) flavor characteristics were linked to alcohols such as heptanol and 1-pentanol, Fuli Ji Braised Chicken (FLJ) flavor was attributed to terpenes including 1,8-cineole and linalool. The flavor profiles of Professor Huang Braised Chicken (PH) were similar to that of Daokou Braised Chicken (DK), with green, fruity, and pungent aromas. The sensory analysis showed that the five types braised chicken had significant differences (P < 0.05), with PH Braised Chicken, DZ Braised Chicken, and JN Braised Chicken exhibiting a more intense meat flavor. This comprehensive analysis of the geographical influence on the flavor profiles and color variations of braised chicken provided a theoretical foundation for enhancing its flavor and overall quality.

Influence of dietary replacement of soybean meal with crawfish shell meals on the growth, skin coloration and muscle texture of Oujiang color common carp (Cyprinus carpio var. color)

An 8-week growth experiment was conducted to investigate the effects of different levels of crawfish shell meals (Procambarus clarkii, CSM) replacement of soybean meal (SM) on growth, feed utilization, antioxidant response, body color and muscle quality of Oujiang color common carp (3.0 ± 0.5g, Cyprinus carpio var. Color), and to assess the suitable range of CSM replacement of soybean meal and its effects on fish. Three isonitrogenous and isolipidic experimental diets were formulated to replace SM by equal proportion (1:1, w: w) of CSM at 0, 25, or 50% (designated as CSM0, CSM25, or CSM50, respectively). The results showed that weight gain (WG) as well as hepatic superoxide dismutase (SOD) activities were significantly (P < 0.05) higher in the CSM25group compared to the CSM0 group. In addition, there were no significant (P > 0.05) differences in growth performance, feed utilization, skin color, and muscle texture parameters between CSM50 and CSM0 groups, except for the overall ash content, which was significantly (P < 0.05) higher in CSM50 than CSM0 group. Therefore, it was feasible to replace 50% of SM with CSM in Oujiang color common carp diets without negative effects on serum biochemical indices, antioxidant and immune responses, skin color or muscle texture. These findings suggested that CSM could be a potential alternative protein source in diets of Oujiang color common carp.

Recyclable and non‐recyclable packaging films with different barrier properties: Effect of processing and storage time on quality of mashed potato and ground carrot

AbstractThe aim of this study was to evaluate if high barrier recyclable material polyethylene/ethylene vinyl alcohol (PE/EVOH) can be an alternative non‐recyclable polyamides (PA)/PE laminate and also if high barrier is required or recyclable PE material with low barrier properties is good enough to maintain the quality of thermally processed mashed potato and ground carrot. The oxygen transmission rate (OTR) of the PA/PE and PE films decreased after heat treatment, while no change was observed for PE/EVOH films. Food contact did not impact the OTR of PA/PE and PE/EVOH films, while the OTR of PE films decreased. The water vapor transmission rate (WVTR) of PA/PE and PE/EVOH films increased after heat treatment. In general, the WVTR of films increased after food contact. The tensile strength of all films was only reduced up to 3–4 weeks of food contact. After 10 weeks, the PE film showed significantly lower hue values and a larger total color difference than the two other films. Light exposure reduced the hue values and increased total color difference after 6 weeks of storage. The odor and flavor of both mashed potatoes and ground carrots were affected by light exposure. The mashed potato showed a slight reduction in freshness‐odor for all materials with storage time. For flavor, mashed potato and ground carrot showed similar trends; flavor was scored unacceptable when packaged in PE films after 6 weeks, but when packaged in PA/PE and PE/EVOH films, the flavor was still acceptable after 10 weeks of storage.

CSPDAE: Colorization via SuperPixel Downsampler Denoising AutoEncoder towards enhanced color structural clarity

Based on the various structural textures, sizes, and shapes of the gray image, the SuperPixel (SP)-based methods convert the rigid pixels into adaptable image patches that share common features. As a result, the SP-based colorization technique not only enhances the color appearance but also preserves the topological integrity of the images. Despite the effectiveness of neural network-based colorization methods, their integration with SP segmentation has traditionally been complex and cumbersome. To address this issue, we propose the Colorization SP Downsampler Denoising AutoEncoder (CSPDAE), where the SP downsampler integrates SP segmentation directly into the network, eliminating the need for any prior input. The SP downsampler addresses the challenges of computational complexity and small region clustering, which are the main obstacles preventing Transformer architectures from being applied to pixel-level segmentation, through the use of SP cross-attention and aggregated positional embedding (APE). Furthermore, we have incorporated a Color Weight (CW) loss, based on the CIEDE2000 color difference formula, to ensure balanced pixel sampling and to improve the precision of detailed color representation. The experimental results confirm the effectiveness of our method, demonstrating its capacity to produce colors with greater structural accuracy and visually appealing details.

Comprehensive impact of pre-treatment methods on white radish quality, water migration, and microstructure

The preprocessing stage is crucial in vegetable processing, significantly influencing the final product's quality. This study investigates the effects of various pre-pre-treatment methods, including cutting, blanching, osmotic, and ultrasound-assisted osmotic treatment, on the quality characteristics, water migration, and microstructure of white radish. The results showed that osmosis and ultrasound-assisted osmosis has the least effect on the total color difference (ΔE) and the greatest water loss (WL) (p < 0.05); blanching has the least effect on the hardness and eutectic points (p < 0.05); and the blanching-ultrasound-assisted osmosis has the greatest solid gain (p < 0.05). The increase of WL led to a decrease in hardness (−0.82). By analyzing the quality characteristics of different pre-treatment methods, contributing to the development of suitable pre-treatment methods for different products and optimization pre-treatments according to requirements. The mechanism of quality characteristics of pre-treatments on products is the future research direction.

Hierarchical sodium titanate supported PdO for high-performance eye-readable hydrogen-leakage detection

PdO pigment is considered as a promising material for eye-readable hydrogen detection. However, the aggregation of the support material will encapsulate PdO nanoparticles and thus significantly weaken the sensing performance. To solve this problem, sodium titanate microscale hierarchical sphere (NTO MHS) is selected as a new support. Thanks to the aggregation-resistant morphology, NTO MHS ensures thoroughly exposure of PdO and facilitates its complete reduction in H2. Therefore, even with a lower PdO loading amount than previous reports, PdO-decorated NTO (PdO-NTO) demonstrates an overall better performance, with a dramatic color difference of 55 and 44 in 4% and 0.3% H2, respectively. The enormous color change at such a low concentration promises PdO-NTO as an outstanding eye-readable hydrogen-leakage warning label. Moreover, we show that the used sensing material can be collected and reactivated repeatedly, further reducing the overall cost. This work highlights the importance of support material designing for PdO-based hydrogen sensors.