High Dynamic Range (HDR) content offers a greater luminance range than Standard Dynamic Range (SDR). Integrating HDR into SDR-dominant user interfaces requires careful consideration due to how the human visual system adapts to surrounding light. This adaptation, known as simultaneous contrast, causes colors to appear darker next to brighter ones and lighter next to darker ones. When HDR is introduced, its higher peak luminance can perceptually dim SDR elements on the screen, making them appear washed out. Applications must manage the brightness of HDR content to avoid negatively impacting SDR assets like text legibility. For mixed HDR and SDR content, a moderate HDR headroom is recommended. Conversely, fully HDR scenes can utilize higher headroom settings. Developers should avoid simply brightening SDR content to compensate, as this can lead to overly bright interfaces. Android 15 introduced specific controls for HDR headroom, allowing developers to request appropriate levels based on content context. Web and Apple platforms also offer mechanisms to constrain HDR brightness in mixed scenes. Thoughtful application of HDR headroom controls is crucial for optimal user experience.