Cats can see in color, although they have trouble distinguishing reds. The color red appears grey to a cat. They are thought to mainly see in greys, blues, and yellows. Cones in a cat's retina allow them to see in color.
Cats do see in color, but not like humans do. Cats don't see the range or vibrancy of colors we do. Blue and green are the colors they perceive the most.