Change the color of a shadow
1. Select the picture, autoshape, wordart or text box you want to change.
2. On the Drawing toolbar, click Shadow Style , and then click Shadow Settings.
3. On the Shadow Settings toolbar, click the arrow next to Shadow Color . Do one of the following:
(a) To change the shadow color back to its default, click Automatic. To change to a color in the color scheme, click one of the colors under Automatic.
(b) To change to a color that isn't in the color scheme, click More Shadow Colors. Click the color you want on the Standard tab, or click the Custom tab to mix your own color, and then click OK.