Cats are the equivalent of human red-green colorblindness in their vision-- which means Zissou can see color better than my roommate!
Here is a really cool site where you can look at things the way your cat does (though it's for human colorblindness). http://colorfilter.wickline.org/
you type in a web address and it filters it to make it look like it would if you're colorblind. I tested it out, and my roommate says the one filtered to his type of colorblindness looks exactly the same as the original. I love scrolling through the petsmart toys department online with this to see what the toys will look like to Zissou.
And they can definitely see color. Zissou likes blues and purples better than warm colors.