How about having a color tone slider with fine saturation and/or white balance controls, similar to what is already in Theme Park? Like when setting up quick panel or a wallpaper theme, the user chooses a certain color and/or hue for parts of the themes they create and then makes into one whole final theme they like. Add a slider control to that final theme that allows an adjustment to the overall saturation of the whole theme. Then they can choose the vividness etc on their creation.
