Color influences flavor expectations and experiences in foods. For example, red can enhance perceived sweetness and green can enhance sourness. Whether color similarly affects flavor perception in e-cigarettes remains unknown. As flavor strongly contributes to e-cigarette appeal, understanding the role of color may inform product regulation. We used a 3 (device color: red, green, reference) ×2 (flavor: tobacco-flavored, flavorless) ×3 (route of administration: seeing, smelling, vaping) mixed design to investigate the influence of e-cigarette color on flavor perception in 63 e-cigarette users. Brown and white devices served as reference colors. Participants rated hedonic and analytical flavor attributes on 101-unit visual analogue scales. In the seeing condition, the flavor of red and green e-cigarettes was expected to be liked (ΔMax= 22) and wanted (ΔMax= 20) more than the flavor of a reference device ΔMax indicates the largest observed difference, and expected to be more familiar (ΔMax= 23), sweet (ΔMax= 28), sour (ΔMax= 40), and fruity. These expectations were confirmed during use (smelling and vaping; where color effects were independent of e-cigarette flavor or route) compared to reference, red and green devices were rated higher in liking (ΔMax= 5), wanting (ΔMax= 6), familiarity (ΔMax= 6), sourness (ΔMax= 9), and fruitiness (ΔMax= 18). Only the red device was rated as sweeter (Δ= 7). Red and green e-cigarettes differed only in expected sourness (seeing condition, Δ= 20). We conclude that device color influences expected and experienced e-cigarette flavor perception and appeal. These findings support regulating color as part of broader flavor restriction policies.
Hellmich et al. (Thu,) studied this question.