What causes you to see rainbow colors out of the side of your eyes?

Seeing rainbow colors out of the side of your eyes, often referred to as "peripheral chromatic aberration," occurs due to the way light is refracted and processed by the eye. The eye's lens and the retina can cause certain wavelengths of light to scatter differently, leading to the perception of colors at the edges of your vision. This phenomenon can be more pronounced under certain lighting conditions or when you're looking at bright objects, as it enhances the contrast and color separation in your peripheral vision.