Hi ya, a lot of games like this tend to put shapes in each bubble like Stars, Triangles or squares etc (like Bust-A-Move and Worms Blast). Games like Puyo Puyo Tetris use different mood faces. :3
Maybe if possible to have something in the options click each bubble and have a color sider and set our own colors? ^^
Don't work too hard on it just to accommodate me though! I'm just one person and no one special! >.<