You can change the Individual Framing Members in a Frame such as the Main Member or Mullion, you can change the Cover Cap to have a different color:

First you have to be in the Frame Editing Mode when changing Individual Members colors. When selecting Individual Members to change the color to:

Select the Individual Framing Members you want to change in the editor then change the color in the Stick properties window. The colors that are available for this particular framing group can then be applied.