I've got grey leather and the only downside I can see is that is shows chocolate stains from when I try to eat Dairy Queen and drive.
Sounds like user error, haha. I am the same way with coffee.
I have tan leather seats in my car. They have worn pretty well--starting to crack a little on the driver's seat but I have 156,000 miles on the car so it's to be expected. My fiancee just got a new car with tan leather seats and interior and the dirty definitely shows up more than dark leather. She wanted to go with darker color but I told her she would be miserable in the summer here.