Colors See Colors Ignore: Clothes Changing ReID with Color Disentanglement

Clothes-Changing Re-Identification (CC-ReID) aims to recognize individuals across different locations and times, irrespective of clothing changes. Existing approaches often rely on additional models or annotated attributes to learn robust, clothing-invariant features, making them resource-intensive. In contrast, we explore the use of color—specifically foreground and background colors—as a lightweight, annotation-free proxy for mitigating appearance bias in ReID models. We propose Colors See, Colors Ignore (CSCI), a RGB-only method that leverages color information directly from raw images or video frames. CSCI efficiently captures color-related appearance bias ('Color See') while disentangling it from identity-relevant ReID features ('Color Ignore'). To achieve this, we introduce \textbf{S2A self-attention}, a novel mechanism designed to separate color and identity cues within the feature space. Our analysis shows a strong correspondence between learned color embeddings and clothing attributes, validating color as an effective proxy when explicit clothing labels are unavailable. We demonstrate the effectiveness of CSCI on both image and video ReID with extensive experiments on four CC-ReID datasets. We improve baseline by Top-1 2.9% on LTCC and 5.0% on PRCC for image-based ReID baseline, and 1.0% on CCVID and 3.6% on MeVID for video-based ReID without relying on additional supervision. Our results highlight the potential of color as a cost-effective solution for addressing appearance bias in CC-ReID.