The impact of correlated colour temperature variation from a tuneable LED lamp on colour sample appearance shift in CIELAB colour space

Abstract

Variation of correlated colour temperature (Tc) of tuneable LED lamps are thought to have a significant effect on red-yellow and blue colour shades, compared to the green one. The phenomenon is expected to be better explained by observing lightness, hue, and chroma (L*C*h°). However, attempts to map the impact of Tc variation on the shift in colour sample appearance are relatively scarce. Therefore, this study aims to map the relation of Tc variation of a tuneable LED lamp with respect to shift in appearance of theoretical colour samples, using L*C*h° parameters in the CIELAB colour space, and to determine their sensitivity. Interaction between SPD of the tuneable LED lamp and ρ(λ) of each colour sample is observed. Analysis is conducted for 210 colour samples derived from the Burns ρ(λ) model. In most cases, as Tc increases, the colour difference tends to become closer to the reference D65. Relation that can be best explained with regression model is the one between the sensitivity of ΔL* and the h° values. The proposed prediction method of colour samples chromaticity under tuneable LED lamps can therefore be implemented in interior lighting scenes with coloured objects and surfaces.