Psychology researcher Mikel Delgado and his team asked 189 people to ascribe traits to pictures of cats, and sorted them to see if they tended to judge a cat by its color.
If you thought the orange cat looked friendly, you're in good company — survey respondents were more likely to attribute friendliness to orange cats than to the other colors (except bi-colored, who are apparently also seen as friendly). The study authors found this a bit surprising, since "depictions of some of the most well-known orange cats in American culture, such as Morris, 'The world’s most finicky cat' and Garfield, who is described as lazy and cynical, are not positive." However, it's possible that "the tendency for orange cats to be highly anthropomorphized in advertising and other popular media influences their popularity. For example, both Morris and Garfield are depicted as being able to talk."
White cats, meanwhile, were more likely than others to be seen as aloof, calm, and shy. Tortoiseshell cats were aloof and intolerant. Black cats were just average at everything — no traits stood out as being more commonly applied to them.
The next question is, why do people believe those things? Is it because of media images like Morris? It may be from the experiences of cat owners, although when generalized to all cats, it sounds like prejudice. I have three cats, and the orange one is the friendly one. The white cat is aloof, and the black cat is the most normal in personality and behavior. How do these traits compare to cats you've had? Link