Are cats color blind?

Cats are not color blind. They see full color but see red poorly. They have high sensitivity to low light images (6 times better than people). This is due to a reflective layer behind the retina that boosts the light hitting the retina. Cats also see detail less well and near range less well. They use their sense of smell more effectively than people. And their whiskers act as a form of sight in darkness.

A cat's eyes are designed for low light level hunting at dawn and dusk and at night.

This page discusses the subject in more detail.