Single‐Layer Vivid‐Colored Radiative Cooling Paint Enabled by Ultrahigh NIR Reflectance

ABSTRACT Radiative cooling is an emerging thermal management technology that cools objects by reflecting solar radiation and emitting heat through the atmospheric transparency window (ATW). Recent studies in radiative cooling have emphasized coating‐ or paint‐based designs for practicality. However, most existing coatings are restricted to white or metallic colors, limiting their use where vivid colors are desired. Colored radiative cooling (CRC) coating is therefore highly valuable, yet many reported designs rely on complex multilayer structures or suffer from performance loss upon coloration. In this study, a single‐layer colored radiative cooling (SCRC) paint that achieves intense coloration and high cooling efficiency is reported. SCRC paints incorporate wide‐bandgap hexagonal boron nitride (h‐BN) particles and hybrid chromatic pigments dispersed in polyurethane (PU) binder. Red, yellow, blue, and white SCRC paints are realized, achieving near‐infrared (NIR) reflectance of 97% for red, yellow, and white, and 90% for blue, despite deep coloration. Significant cooling was observed compared to commercial paints of similar colors, with temperature reductions exceeding 6°C for red, yellow, and white, and 4°C for blue. These findings demonstrate that SCRC paints uniquely integrate vivid coloration, structural simplicity, and robust cooling performance, offering a practical route for real‐world applications.