I thought I wouldn't like red leather until I saw a white BMW 328 with red leather. It looked really nice. I wouldn't mind seeing that as an option. I most likely won't get it because I'm afraid that I will get tired of it too fast, but I'm sure some others will appreciate it.
I would not have animal leather regardless of color. A big reason I drive electric with the vegan interior is "greenness" and the waste and negative environmental effects of the livestock industry sullies that.
I think Tesla should offer a red leather option and a Black/Red hybrid option (bed in the middle of the seats and black on each side of the seat). However, I think the red leather would only look good on with the carbon fiber accents and only with certain exterior colors. The wood accents would not look well with the red interior. I think Tesla kind of streamlined the options to choose from so no matter what exterior color or interior accents you choose all of the seat colors will work.