This is also known as the Kaleidoscopic Effect.
These halos are known as 22-degree halos because the halo or ring has an apparent radius of 22 degrees around the sun/moon.
Cirrus clouds, which are thin, detached, hair-like clouds, produce circular halos in particular. These clouds form at a height of more than 20,000 feet in the .
A halo, like a rainbow, is visible when viewed from the right angle, sometimes appearing only white but often with colours from the spectrum clearly visible.