Occasionally I will do marker color comps to show Seonna for the color script (I can't whip out a gorgeous painting quite as efficiently as she does). I will usually do this when I have a particular idea about how the characters should relate to the backgrounds (the character color models aren't created until the backgrounds have already been painted). "Mind over Matter" was an especially challenging episode to find a color-arc for, the entire story was supposed to take place in the dark!
Note the Jenny fountain in the lower right where we changed our minds about her color. One important rule for coloring characters is that they should always pop off the background (this was especially truein this scene).