Orange. It's also the best tasting colour!
Fun fact: Contrary to popular belief, oranges weren't actually named because of their colour, in fact, the colour is named after the fruit (in a similar way to the much less awesome colour, "Plum"). Before the invention of Oranges, it was simply referred to as "Light Red", a label that has now been picked up by people who want to make pink seem manly (tip: it isn't). Presumably this is what sparked the renaissance, though I have no means to back up this claim.
Seriously though, could you imagine what other colours taste like? I always though green would taste of wax crayons, and blue kinda like toilet duck (not that I'd know what either of those taste like) red might taste nice, but it's no orange! I don't think Cyan would have a taste at all. It seemed to have spent all it's points on being bright (have you ever seen a dark cyan? Teal doesn't count, for obvious reasons) and couldn't afford any more interesting attributes. Purple... maybe... it wouldn't taste bad, but I imagine there are better tasting colours. As for yellow. Ergh. No thank you.
That only leaves black and white. And anyone who says they taste any different is a racist. And also a cannibal. I don't need to hear the opinion of no racist cannibals, thank you sir!