This study investigates what is perceptually the most optimal way to create a temporal color transition between two colors. The first experiment measured the ability to distinguish between two temporal color transitions. The reference transition was a linear interpolation between two colors in CIELab, the test transitions were arcs defined in different planes going through the linear transition. Discrimination thresholds ranged between 2.5 and 10.5 ΔEab, dependent on the color pair, direction and duration of the transition. In the second experiment, several perceptually different color transitions were evaluated. The most preferred transitions were a linear transition in CIELab and a linear transition in RGB. This suggests that appealing temporal color transitions can be created without complicated calculations.
Ingrid Vogels, Dragan Sekulovski, Bartjan Rijs, "Discrimination and preference of temporal color transitions" in Proc. IS&T 15th Color and Imaging Conf., 2007, pp 118 - 121, https://doi.org/10.2352/CIC.2007.15.1.art00022