adobe photoshop - How to select a global fill color for shapes

Working with Photoshop CS4, I have a file with 4 shapes and some portion of the same shapes to create overlay effects, I need to color a set of shapes with color A and the other set with color B, since the shapes are in the same group to create the overlay with partial shapes I need to define a global color A and global colo B is it actually possible?

Answer

While Photoshop does work with shapes, it is mainly a photo-editing tool. Conversely, Illustrator's main purpose is to work with shapes (not photos) and provides additional features, one of which is 'Global Colors'. See this question or just search 'global' in the official AI docs.