I know your post just asks for one, but why not have both (the red one in fall/winter, the other in other seasons) if you're going to be actively playing the game? I guess it might be a bit of a hassle to plant if you have lots of flowers...
I would personally go with white, black, and just a small smattering of gold in spring and summer, then white, red, and the gold in fall and winter (red goes well with the fall and it stands out in the snow). Basically, you'd be switching out black for reds, and you can sort of imagine them to be cool colour-changing flowers
- - - Post Merge - - -
Oh, sorry, I don't know why I thought you were talking about flowers! lol
I guess you can't really change villagers' houses or anything... Then I would go with the first option!