Color Mixing Theory Research Articles

Study of Material Color Influences on Mechanical Characteristics of Fused Deposition Modeling Parts.

The objective of the present work is to evaluate the influence of material color on mechanical properties of fused deposition modeling (FDM) parts. The performance of the products is evaluated by testing eight different colors of acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) material in terms of tensile strength, compressive strength, and flexural strength. The analysis of data shows a significant difference in mechanical characteristics of prints depending on filament color. For different colors, these three strengths almost follow the same rising and falling tendency. In order to explore the relationship between mechanical strengths and filament colors, the color-mixing theory and the least-squares method are adopted to fit the best ratio coefficients of different color combinations. Results are presented showing that the strength value (e.g., tensile) of the mixed color can be evaluated through that of primary colors by fitting the other strength (e.g., compressive or flexural). It is shown that the predicted value is always no more than 7% error compared with the actual strength, in spite of two-color or three-color mixtures. An additional confirmation test with seven colored PLA filaments from different suppliers was conducted to focus on the extensibility. The outcomes show the maximum fitting errors of strengths for mixed colors in all cases are within 5%, proving the effectiveness and applicability of this predicted approach. This study can bring a detailed analysis that enables better estimation of the function of material color and contributes to improving the property of FDM printed products for consumers by choosing the suitable filament color.

Design of smart light source based on bi-color LED with single duty cycle for correlated color temperature adjustment

Color-adjustable light sources facilitate both mood lighting and daylight harvesting. A single duty cycle can be used by a bi-color LED to adjust the correlated color temperature (CCT) by associating it with the duty cycle of the pulse width modulation dimming signal of the cool and warm white LEDs. The one-to-one mapping relationship between the single duty cycle and the CCT is based on the color mixing theory of bi-color LEDs. A method to correlate the dimming signals for bi-color LEDs is presented. The influence of the time characteristics of the two basic signals on dimming and CCT adjustment is analyzed. The dimming system of bi-color LEDs is designed, and the method used to adjust the CCT with a single duty cycle is verified. The experiment showed that the CCT can be accurately adjusted by the proposed method.

A feasible strategy of Prussian blue reflective electrochromic devices capable of reversible switching between sand-yellow and leaf-green

A flexible reflective-type electrochromic device based on PB films has been constructed. Based on the subtractive color-mixing theory, the demonstrated electrochromic device exhibits a unique reversible color changes from leaf-green to sand-yellow by electrochemical operation. Fast response time of 0.9 s for bleaching and 1.3 s for coloring is observed, which is faster than most reports. In addition, the device exhibits high electrochromic stability of more than 100 cycles without compromising its performance. The flexible device shows promise for a broad range of potential application in the wearable electrochromic displays and camouflage.

RGB-to-black multicolor electrochromic devices enabled with viologen functionalized polyhedral oligomeric silsesquioxanes

Here we demonstrate multicolor electrochromic transitions of viologen functionalized polyhedral oligomeric silsesquioxanes (POSS-viologens). Highly efficient RGB coverage, including black, was successfully achieved with POSS-viologen employed multi-stacked electrochromic devices (ECDs). We prepared octa-viologen functionalized POSS (OHV-POSS) with the insertion of thiophene (OTxHV-POSS) and phenyl (OPhHV-POSS) moiety. The single-layer ion gel ECDs exhibited outstanding electrochromic performances. OTxHV-POSS and OHV-POSS showed red (R) and blue (B) transitions, respectively, with high transmittance changes and superb coloration efficiency. Saturated green (G) was also obtained from the mixture of OPhHV-POSS and OHV-POSS. Furthermore, multi-stacked ECDs were implemented by combining the RGB coloration layers with multiple electrodes. The two-layer ECDs generated intermediate colors, which was fully translated into the color mixing theory. The three-layer device created real black with blackness L∗ of 6.99, covering 12.9% of the NTSC color gamut. The unprecedented RGB-to-black multicolor coverage, not reported elsewhere, is attributable to the reversible color-switching at a low redox potential for extended cyclic operations. Current findings imply that carefully designed POSS-viologens offer a universal route to high-performance and stable multicolor ECDs, offering compatibility with various pixelized color-changing displays and smart windows.

Low cost, high color rendition, CCT variable lighting system based on W-G-B LED

This article proposes a novel approach of tunable correlated color temperature (CCT) lighting system with high color rendition using three component color mixing concept. Using Grassmann’s color mixing theory, phosphor coated warm white LED source (CCT 2800 K) is mixed with the blue (467 nm) and green (527 nm) LED light sources and a detailed mathematical formulation is derived for easy controlling of variable CCT and experimentally validated in this article. As a result, the locus of the blended light source is very close to the Planckian locus on Commission Internationale de l’Eclairage (CIE) 1931 chromaticity diagram. The generated color of the light sources is evaluated by both CIE color rendering index (CRI) method and Illuminating Engineering Society (IES) TM-30-18 method. This proposed system provides a wide range of CCTs starting from 2800 K to 7500 K with a very high CRI (CIE Ra) value of 94, color fidelity index (IES Rf) score of around 85 and color gamut index (IES Rg) of 95. As this system uses only three color component, the cost of this system is comparatively low with respect to other high CRI, tunable CCT lighting system available in market.

Color combination of polysiloxane polymer by introducing two different triphenylamine based pendent groups for electrochromism

ABSTRACTA novel triphenylamine (TPA)‐containing polysiloxane (PTPASi) named P(PT‐TB‐TPA)Si has been synthesized through hydrosilylation method by the reaction of poly(methylhydrosiloxane) (PMHS) with two different TPA‐based alkenes (TPAA) simultaneously for electrochromic application. The thermal stability and cycling stability of the P(PT‐TB‐TPA)Si were enhanced by grafting TPA onto polysiloxane since the force of adhesion between the P(PT‐TB‐TPA)Si film and the ITO substrate can be improved. The morphology of the polymer after electro‐oxidation was investigated and no significant change was observed revealing good stability. Otherwise, the effect of two different TPA‐based alkenes which were introduced into one polymer through covalent bond on cyclic voltammetry and electrochromic spectra was studied. The color of the polymer changed from colorless to red then to deep purple which obeys the color mixing theory and reveals multielectrochromic property. In addition, the potential switching property of the P(PT‐TB‐TPA)Si at the temperature of 150 °C has been investigated. The high thermal stability makes the polymer potential for relatively high temperature and/or long‐term cycling application. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46522.

Grafting triphenylamine groups onto polysiloxanes to improve interaction between the electrochromic films and ITO

A novel series of triphenylamine (TPA)-contained polysiloxanes (PTPASi) have been synthesized by a normal reaction of hydrosilylation through poly(methylhydrosiloxane)(PMHS) with four TPA-based alkenes (TPAA) for electrochromic applications. Grafting TPA onto polysiloxanes was employed as a strategy to ameliorate the thermal stability and cycle stability of the electrochromic properties due to the enhanced force of adhesion between the polymer films and the ITO substrate. The morphology and impedance of the polymers after electro-oxidizing reaction was studied and didn’t reveal significant change suggesting good stability of the hybrid system. Meanwhile, with the introducing of the polysiloxane backbones, the four polymer films appeared nearly colorless in their natural state, in contrast to three primary colors of red, green and blue in their oxidized state. Hence, these PMHS films can be mixed to obtain all the other colors on the basis of the color mixing theory. In addition, the potential switching properties of the four polymers at the temperature of 150°C have been investigated for the first time, which indicate high thermal stability and potential for relatively high temperature and/or long term cycling applications.

Spectral design and evaluation of OLEDs as light sources

Organic light-emitting diode (OLED) will possibly become the mainstream in lighting technology given that its features, such as self-luminosity, deflectivity, and penetrability, are different from those of common light sources. Studies on OLEDs have generally focused on the luminous efficiency of its components; however, selecting an optimum color mixing spectrum for OLEDs to apply on illumination has seldom been discussed. In this study, color mixing is conducted by combining two and three colors based on color mixing theory. Through screenings that employ related evaluation techniques such as chroma standard and color rendering, we identify a set of optimum color mixing spectra at different correlated color temperatures that will be evaluated via the color rendering index (CRI), the color quality scale (CQS), and the feeling of contrast index (FCI). The CRI and CQS of simulative OLED light sources exhibit better performance at correlated color temperatures of 3000, 3500, 4000, and 4500K than those of standard light sources of the Commission Internationale de l′Eclairage, whereas the FCI is increased to a range of 3–30%. The illumination images of standard and simulative light sources can be reproduced by using multi-spectral imaging. In this study, we attempt to explain the research direction of colors, which should be discussed in future studies on OLEDs, by applying several methods to evaluate light sources as well as color-image rendition technology.

Members of CMY Color Space: Cyan and Magenta Colored Polymers Based on Oxadiazole Acceptor Unit

In this study, three novel oxadiazole-based polymers were synthesized and their electrochemical and optical properties were investigated. The polymers were found to have both p- and n-type doping properties accompanied by electrochromic response. Two polymer films exhibit cyan and magenta colors, which constitute two legs of CMY color spaces, in their neutral states and they are soluble in common-organic solvents. According to the color mixing theory, all colors in the visible spectrum including black color can be obtained by using these polymers with a yellow colored electrochromic polymer. Among these polymers, the polymer bearing propyledioxythiophene donor units has some superior properties like high stability (it retains 94% of its electroactivity after 2000 cycles), solubility, and high coloration efficiency (230 cm2/C), whereas as expected ethylenedioxythiophene containing one has the lowest band gap as 1.08 eV.

The Research of Printing Quality Based on <i>Tri stimulus</i> Value

In order to meet the limitation of density detection based on color mixing theory in traditional printing quality control, the study has established a relational model for colorimetric tri-stimulus value and ink feeding volume. It builds a colorimetric mathematical model from the offset printing proof, and uses the regression theory to correct the metring model and determine the dummy blackprint. So it can solve the problem of indeterminate solution in conversion process from tri-stimulus value to dot coverage. It fits the functional relationship through both dot area variation value and dot density variation value accessed via Yule - Nielsen formula so as to connect them. The experiment shows that it is available to get ink volume deviation with standard proof by chromaticity measurement, and there is a significant linear relationship between the corrected Neugebauer equation coefficient and tri-stimulus value. After normalizing the precision of Neugebauer equation which has been improved, the nonlinear relationship exists both in density variation value and area variation value, and the precision of the model is well and can be applied to the actual manufacture.

Design Considerations Between Color Gamut and Brightness for Multi-Primary Color Displays

Color displays show a vivid colorful image by combination of three or above primary colors on every individual pixel. Brightness of color displays, however, strongly restricts the color gamut of displays. From the color mixing theory, the area of color gamut on the color coordination would shrink smaller when brightness grows up. At the maximal brightness, displays can show one system white point only. The difficulties how to obtain the maximal brightness under an assigned color point or color gamut have been a key issue for display manufacturers. The paper proposes a theory to analyze the relation between brightness and color gamut based on the multi-primary color display. Simulations estimate the boundary of color gamut of multi-primary color displays under required brightness which had been proved by experimental results of tri-primary color display. The theory can be applied on the color temperature (CT) design which experimental results show the fact that a display apparatus with higher color temperature could sacrifice brightness less compared to one with lower color temperature when color temperature of the display image needs to change. The theory provides a design guideline for optimization between color gamut, color temperature and brightness on multi-primary color displays

Artists' Colors and Newton's Colors

Previous articleNext article No AccessArtists' Colors and Newton's ColorsAlan E. ShapiroAlan E. Shapiro Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Isis Volume 85, Number 4Dec., 1994 Publication of the History of Science Society Article DOIhttps://doi.org/10.1086/356979 Views: 42Total views on this site Citations: 24Citations are reported from Crossref Copyright 1994 History of Science Society, Inc.PDF download Crossref reports the following articles citing this article:Eric Kirchner, Phil Koken The art of painting rainbows—between color science and painter's practice, Color Research & Application 47, no.66 (Jul 2022): 1372–1391.https://doi.org/10.1002/col.22810Tawrin Baker Color in the Early Modern Period, (Aug 2022): 339–348.https://doi.org/10.1007/978-3-319-31069-5_455Joshua Schouten de Jel The Epicurean and Lucretian Slur: Isaac Newton, (Nov 2021): 63–109.https://doi.org/10.1007/978-3-030-88888-6_3Alice Ottazzi Il pastello nel Settecento europeo tra sapere scientifico e pratica artistica, Venezia Arti , no.11 (Dec 2020).https://doi.org/10.30687/VA/2385-2720/2020/01/005Renzo Shamey, Eric Kirchner, Seyed Hossein Amirshahi Tusi, Nasir al-Din 1201–1274, (Nov 2020): 49–53.https://doi.org/10.1007/978-3-319-30811-1_11Baker Tawrin Color in the Early Modern Period, (May 2020): 1–10.https://doi.org/10.1007/978-3-319-20791-9_455-1Sachiko Kusukawa The Early Royal Society and Visual Culture, Perspectives on Science 27, no.33 (Jun 2019): 350–394.https://doi.org/10.1162/posc_a_00311Giulia Simonini Organising Colours: Patrick Syme’s Colour Chart and Nomenclature for Scientific Purposes, XVII-XVIII , no.7575 (Dec 2018).https://doi.org/10.4000/1718.1327Dan Kervick Hume's Colors and Newton's Colored Lights, Journal of Scottish Philosophy 16, no.11 (Mar 2018): 1–18.https://doi.org/10.3366/jsp.2018.0180Paulo Maurício, Bianor Valente, Isabel Chagas A Teaching-Learning Sequence of Colour Informed by History and Philosophy of Science, International Journal of Science and Mathematics Education 15, no.77 (Mar 2016): 1177–1194.https://doi.org/10.1007/s10763-016-9736-8 Kapitel III: Farbe als Sprache, (Jan 2017): 165–266.https://doi.org/10.7788/9783412509941.165Eric Kirchner, Seyed Hossein Amirshahi Al-Tusi, Nasir al-Din, (Jul 2016): 18–19.https://doi.org/10.1007/978-1-4419-8071-7_334Natascha WANNINGER Theatrical Colours: Cosmetics, Rhetoric and Theatre in Webster’s The White Devil, E-rea , no.12.212.2 (Jun 2015).https://doi.org/10.4000/erea.4475Eric Kirchner Color theory and color order in medieval Islam: A review, Color Research & Application 40, no.11 (Dec 2013): 5–16.https://doi.org/10.1002/col.21861Eric Kirchner, Seyed Hossein Amirshahi Al-Tusi, Nasir al-Din, (Aug 2015): 1–3.https://doi.org/10.1007/978-3-642-27851-8_334-1Eileen Reeves The New Sciences and the Visual Arts, (Feb 2013): 316–335.https://doi.org/10.1002/9781118391488.ch15Eric Kirchner, Mohammad Bagheri Color Theory in Medieval Islamic Lapidaries: Nıshābūrı, Tūsı and Kāshānı, Centaurus 55, no.11 (Sep 2012): 1–19.https://doi.org/10.1111/1600-0498.12000James Delbourgo The Newtonian slave body: Racial enlightenment in the Atlantic World, Atlantic Studies 9, no.22 (Jun 2012): 185–207.https://doi.org/10.1080/14788810.2012.666412John Gage Signs of Disharmony: Newton's Opticks and the Artists, Perspectives on Science 16, no.44 (Dec 2008): 360–377.https://doi.org/10.1162/posc.2008.16.4.360John Henry The Fragmentation of Renaissance Occultism and the Decline of Magic, History of Science 46, no.11 (Mar 2008): 1–48.https://doi.org/10.1177/007327530804600101Sven Dupré Galileo's Telescope and Celestial Light, Journal for the History of Astronomy 34, no.44 (Nov 2016): 369–399.https://doi.org/10.1177/002182860303400402Agustí Nieto-Galan Artisans and Artists in Dyeing and Printing, (Jan 2001): 153–180.https://doi.org/10.1007/978-94-017-1081-7_5Martin Gersch Geschäftsbeziehungsmanagement bei integrativer Leistungserstellung, (Jan 1998): 75–189.https://doi.org/10.1007/978-3-322-89127-3_3 John Neu Current Bibliography of the History of Science and Its Cultural Influences, 1995, Isis 86 (Oct 2015): 1–331.https://doi.org/10.1086/357399

Recent advances in retinex theory and some implications for cortical computations: color vision and the natural image.

Recent advances in retinex theory and some implications for cortical computations: color vision and the natural image.