Clouds, Halos, and Rainbows

Halos:

A halo is a ring or light that forms around the sun or moon as the sun or moon light refracts off ice crystals present in a thin veil of cirrus clouds. The halo is usually seen as a bright, white ring although sometimes it can have color. https://www.weather.gov/arx/why_halos_sundogs_pillars

A rainbow is caused by sunlight and atmospheric conditions. Light enters a water droplet, slowing down and bending as it goes from air to denser water. The light reflects off the inside of the droplet, separating into its component wavelengths–or colors. When light exits the droplet, it makes a rainbow. https://scijinks.gov/rainbow/