Chromatic Asymmetry in Visual Attention: Dissociable Effects of Background Color on Capture and Processing During Reading—An Eye-Tracking Study

Visual attention mechanisms are modulated by chromatic properties of the environment, with significant implications for human–computer interaction, interface design, and cognitive ergonomics. Despite extensive research on color perception, a critical gap remains in understanding how background colors differentially affect initial attentional capture versus sustained processing efficiency during text reading. This study investigates how seven different background colors (yellow, orange, red, green, blue, purple, and black) influence visual attention and cognitive load during standardized reading tasks with white text, revealing a fundamental asymmetry in chromatic processing stages. Using high-frequency eye-tracking at 120 Hz with 30 participants in a within-subjects design, we measured time-to-first fixation, total viewing duration, fixation count, and revisitation frequency across chromatic conditions. Non-parametric statistical analyses (Friedman test for omnibus comparisons, Wilcoxon signed-rank test for pairwise comparisons) revealed a systematic dissociation between preattentive capture and sustained processing. Yellow backgrounds enabled the fastest initial attentional capture (0.65 s), while black backgrounds produced the slowest detection (1.75 s). However, this pattern reversed during sustained processing: black backgrounds enabled the shortest total viewing time (0.88 s) through efficient information sampling (median 5.0 fixations), while yellow required the longest viewing duration (1.75 s) with fewer fixations (median 3.0). Statistical comparisons confirmed significant differences across conditions (Friedman test: χ2(6)=138.4–154.2, all p<0.001; pairwise comparisons with Bonferroni correction: α=0.0024). We note that luminance and chromatic contrast were not independently controlled, as colors inherently vary in both dimensions in realistic interface design. Consequently, the observed effects reflect the combined influence of hue, saturation, and luminance contrast as they naturally co-occur. These findings reveal a descriptive pattern consistent with functionally distinct mechanisms, where chromatic salience appears to facilitate preattentive capture while luminance contrast appears to determine sustained processing efficiency, with optimal colors for one stage being suboptimal for the other under the present experimental conditions. This observed chromatic asymmetry suggests potential implications for interface design: warm colors like yellow may optimize rapid attention capture for alerts and warnings, while high-contrast combinations like white-on-black may optimize sustained reading efficiency, though these preliminary patterns require validation across diverse contexts. Green and purple backgrounds offer balanced performance across both processing stages, representing near-symmetric solutions suitable for mixed-task interfaces. Given the controlled laboratory setting, university student sample, and 15 s exposure duration, design recommendations should be considered preliminary and validated in diverse real-world contexts.