➡ The best performing CoolRoof will necessarily be white :

1. To be refreshing, the sun’s rays (UV + visible + near-infrared) must be reflected.
2. White reflects the fact that all visible solar rays are reflected.
3. The color reflects the fact that some of the (visible) solar rays are absorbed, and therefore contribute to heat absorption.

However, it’s worth considering this issue because in some cases, ultra-white can be problematic (glare, urban planning regulations, etc.). In this case, you should always favor a light appearance and ensure that solar reflectance in the near-infrared range remains at its maximum.

It is also important to keep in mind that, just as nothing will perform better than white, nothing will perform worse than black (which absorbs all of the sun’s visible rays).

Conclusion with an example : A “sky blue” cool roof will not perform as well as a white cool roof, but will still perform better than a black coating.