Sniffing colors-color associations for descriptors and odors of the MONEX-40 test

Research on odor-color associations provides insights into brain processes that integrate attributes from seemingly independent senses, forming crossmodal correspondences. Since multisensory integration is based, among others, on semantic congruency, we aimed to provide a color profile-encompassing hue, saturation, and lightness-for the standardized MONEX-40 test. This color profile will enable the use of odor-congruent or odor-incongruent colors in olfactory-visual studies. In Study 1, participants completed an online survey, selecting colors corresponding to each descriptor in the smell test. The analysis revealed distinct color patterns, highlighting the importance of learning in descriptor-color associations. Study 2 explored color associations for all 40 odors of the MONEX-40 at different time points. Initially, participants reported color associations based solely on odor perception. Then, they identified the odor from a set of four descriptors and reassigned colors after odor identification. Both qualitative and quantitative methods, including statistical tests and Delta E (CIE 2000) analysis, demonstrated shifts in color associations after odor identification, affecting hue, saturation, and lightness. This research deepens our understanding of how color associations form in response to various stimuli, including descriptors and odors. The findings have scientific relevance, as mentioned above, but also practical applications in product development, particularly in the food and cosmetics industries, where combining specific colors and odors can enhance product appeal.