What you’re seeing is a 22° solar halo

 What you’re seeing is a 22° solar halo, formed when sunlight passes through millions of tiny hexagonal ice crystals suspended in high-altitude cirrus clouds. Each crystal bends the light at a precise angle, separating it into a faint spectrum and creating a perfect ring around the Sun.

The warm colors come from the low Sun near the horizon, where longer wavelengths scatter less and dominate the sky. The ring looks rare because the conditions must align exactly — crystal shape, cloud height, and solar angle — and they usually last only minutes.