Step 6. Let's add a gradient fill to the mask to get away from only solid colors and add some visual interest to the composition.

Select all the transparent areas of the mask except the eyes, mouth and circles on the forehead. Open a new layer and name it gradient. Select the Linear Gradient tool from the toolbox (circled in red to the left). Make sure the Options palette is visible on your screen. (If it’s not, choose Window > Show > Options.)

On the Linear Gradient Options palette, select a gradient from the list. I chose Red, Green. Now click Edit to bring up the Gradient Editor. Red, Green should already be selected in the list. If it’s not, select it. Make sure Color is selected for Adjust. Next edit the midpoint of the gradient by dragging the diamond above the gradient color bar until you're satisfied with the gradient’s color transition. Do you want more red and less green or vice versa? Play with it until you get the gradient you want. Click OK.

To apply the gradient to the mask position the mouse pointer over the mask image where you want the gradient to begin and drag to the endpoint. I started in the lower right section of the mask and dragged to the upper left to apply the gradient at an angle.