A couple of existing questions, answers and comments How can I train my cats to only eat from their own bowls? and Can cats see optical illusions the same way we can? involve cats' color perception. Do cats have the same range of color perception as people? If not, how does it differ? What colors, that I see as different, would a cat see as the same?
All I read about colour vision of cats state:
Cats have only two colour receptors (green and blue), where humans have three (green, blue and red). So, probably everything which appears red to us, may be a very pale green to a cat.
On top of that, cats have much more rods in their retina than we have. This (and their reflecting sheet under their retina) increases the sensitivity to low light by six, which enables them to be night hunters. As for nearly all animals night vision is only grayscale. On the contrary, day vision, which is provided by the cones and rods, enables colour vision. But due to the lower count of cones (in exchange to the higher number of rods) the colour vision of cats is probably rather dim. We could imaging them seeing everything in pastel colours without any vivid colours.
However there is no way to explain the way a cat or any animal with different retina perceives their environment correctly, because the matter of vision is a highly subjective one.