It would be easy to assume that animals can see the same things as humans, but this is not always true! Some horses seem to spook at brightly colored objects, but what colors do horses see?
The cones in the retina of the horse’s eye can detect blue light and yellow-green light. This enables them to see all shades of blue, green, and yellow, but not red.
So, as we have learned, horses can see the colors yellow, green, and blue. They cannot identify the color red, which will appear gray to a horse. Horses have very good vision and are especially good at seeing in low light.