# Device color influences e-cigarette flavor expectations, perception, and appeal

## TL;DR

The color of e-cigarettes affects how users expect and experience their flavors, which could help in regulating these products.

## Contribution

This study shows that device color influences e-cigarette flavor perception and appeal, offering new insights for regulation.

## Key findings

- Red and green e-cigarettes were expected and experienced as more sweet, sour, and fruity compared to reference colors.
- Color effects on flavor perception were consistent across seeing, smelling, and vaping conditions.
- Device color could be regulated as part of broader flavor restriction policies.

## Abstract

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 analog 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.