Tunable color display and efficient thermal regulation with grating colored radiative cooler

Integrating color display with radiative cooling is of great importance for applications in both aesthetic appeal and thermal management. However, current colored radiative coolers primarily rely on geometric modulation, resulting in monochromatic color and limiting their applicability. Here, we present a tunable colored radiative cooler (GCRC) comprising an upper grating emitter and a lower grating reflector. The emitter achieves a high average emissivity of 98.8% and 86.5% within the first and second atmospheric transparency windows simultaneously, and it demonstrates angular-insensitive emissivity (>70%) across 0–90° incident angle. Meanwhile, the grating reflector enables dynamic color manipulation through variations in polarization angle, dielectric layer thickness, and grating filling fraction. Notably, the GCRC demonstrates a maximum net nighttime cooling power of 232.08 W·m⁻² at 300 K, and it reaches up to 74.6 W·m⁻² under solar irradiation. Thus, our design not only delivers vibrant, adjustable color but also outperforms conventional radiative coolers in terms of cooling efficiency, making it a promising solution for architectural coatings, smart aesthetics, and advanced thermal management systems.