The rims with the black centers can only have the center color changed. I think adding a secondary color option for rims like that would allow better and more vast customization options.
Example: Keeping the center black, but changing the outer to be gold, or making the center red and the outer green for a festive look on other rims than the regular Christmas ones. Even the Christmas rims could be changed to have blue trees, or the Easter rim could have 3 different colored spokes AND and main color. Now THAT would have many possibilities.
