CIELab-Based Color Combinations Proposals for Maximizing Motion Illusion Effects Centered on Hue Angles(Theta)

This study aims to enhance the experience of motion illusions by proposing color combinations based on the CIELab color space and refining existing motion illusion design principles. This research highlights that conventional design rules predominantly focus on the luminance difference, suggesting the potential involvement of hue in influencing the illusion. To this end, an experimental model was developed to analyze how variations in lightness and hue affect the intensity of the illusion. This model employs the CIELab color space, which allows the interpretation of color attributes in alignment with human perceptual levels. The experiment used the wave illusion pattern, which enables the perception of wave-like motion in static images. The lightness and hue angle (Theta) of the background and foreground were set as variables. The experiment involved 30 adults aged 19–35 years, excluding individuals with difficulties in color or illusion perception. Participants were tasked with selecting multiple foreground theta that elicited strong illusion for a given background color under eight lightness conditions with chroma set at 100. They also identified background theta that disrupted the illusion and rated the overall intensity of the illusion under each lightness condition using a 5-point Likert scale. The results were quantitatively analyzed using one-way ANOVA and repeated measures ANOVA (RM ANOVA) and were further validated through qualitative analysis. The findings aim to overcome the limitations of prior studies that focused solely on luminance and propose optimal color combinations by considering hue to maximize the motion illusion experience. This research refines the existing color conditions for motion illusions and provides clearer and more robust guidelines, potentially broadening the scope of motion illusion studies. Furthermore, these guidelines could be directly applied to motion illusion-based designs, contributing to the practical and creative utilization of such designs.