Hamilton may not be happy with a black one, but also Ferrari wouldn't want a black one neither, as a team. Even if marketing ever suggested it, all other departments will say no to that with ease. Ferrari is red, that's just how it is, and I do not mean about the general car color for formula neither, I am talking about literally regular cars as well.

If you ever bought a Ferrari, would you rather have a black one? I would not consider any other color than red ever, because that's the color of the brand. Other brands could have red cars too, it is not like against the law or anything, but when you see a red Mercedes, or a red BMW, it is not the same feeling as seeing a red Ferrari. Hence, the color is out of question.