Seeing Scents: The Cross-Modal Impact of Visual Cues on Fragrance Mixture Perception

This study investigated whether the colour of smelling blotters subtly changed how people sense binary fragrance mixtures. Building on work showing single odours can feel sweeter or grassier when matched with certain shades, the project tested more complex blends that combine fruity γ-nonalactone with grassy cis-3-hexenol in balanced and asymmetrical ratios. Thirty-five adults first completed threshold and colour-association tasks, confirming yellow as the intuitive partner for γ-nonalactone and green for cis-3-hexenol. Intensity-matched mixtures were then applied to yellow, green, black, or white blotters, and participants rated fruity/sweet strength in a Latin-square sequence. Repeated-measures ANOVA and paired t-tests showed no statistically significant main effect of blotter colour; however, systematic trends emerged. Green backgrounds tended to dampen fruity/sweet impressions, even when cis-3-hexenol was dominant. Yellow, despite being semantically congruent with γ-nonalactone, sometimes lowered perceived sweetness, suggesting congruency alone cannot guarantee enhancement. Unexpectedly, black blotters boosted fruity/sweet ratings across all formulas, hinting that high-contrast, non-associative cues may override colour–odour pairings. Although subtle, these cross-modal shifts underscore the importance of perceptual dominance and visual framing when designing fragranced products, especially those relying on nuanced mixture profiles. Future work should test broader note families, consumer groups, and real packaging contexts for commercial use.