Gabriel Conn¹, Zephyr Markley¹, Katie Jobson², Kayla Sansevere³, Katherine Moore¹; ¹Arcadia University, ²University of Pennsylvania, ³Tufts University

Visual search depends on internal search templates that guide attention toward likely targets while filtering distractors. These templates, stored in activated long-term memory, can shift flexibly depending on task demands and display context. One factor influencing template formation is color constancy—the perceptual adjustment that maintains stable color appearance across changes in lighting. We investigated whether perceived lighting changes automatically reshape visual search templates, even when such adjustments hinder performance. Participants searched a rapid serial visual presentation for a target presented while background and distractor colors were systematically shifted in hue to simulate lighting changes. There were two critical distractors for each target, which were generated by applying red and green filters to the target. Participants were instructed to reject these distractors. Across four experiments and six unique targets using a dynamic display, participants consistently showed greater difficulty rejecting distractors whose color shifts matched the background tint, i.e., distractors that appeared as a target would have had there been a true lighting change. Target identification also suffered on tinted backgrounds relative to white. These effects were amplified when the background color persisted across trials as opposed to when it changed randomly, suggesting that establishing a lighting context strengthens template shifts. We found similar effects in static displays of realistic visual scenes. These findings demonstrate that color constancy principles influence visual search automatically, constraining strategic control over search templates. This reflexive adjustment, while sometimes counterproductive as in the case of this study, is reflective of an adaptive mechanism for object recognition in natural environments.