I would say the consumer wanting a MacBook Pro isn't looking for a green or orange one. Also colorful laptops like the old iBooks aren't as popular anymore and I'm sure that's why Apple isn't currently doing it. Niche colors don't sell well.
Surprisingly, it's not getting much hotter due to black body radiation. I spoke to the inventor of Vantablack because we created a super black tshirt and he confirmed.