Do you think they'd allow borders on the... well, borders? I mean, I agree we can't have red, too generic, and that black itself is can be a depressing and boring colour. But, what if we use black as a base and border it with a more vibrant colour, like violet or (the terrifying sounding) plum purple I think it would give sense of boldness, strength and wealth while the border would add some royalty, wisdom and prosperity to the mix. I've done it on my nation a little in Microsoft paint and it actually looked alright. Whether or not you guys think so is up to you, and there is a great chance that a border wouldn't be allowed, but I like this idea. However, I'm a bit stumped if we have to choose a single colour.