I needa few directions creating a sig (this is not a sig request)

im trying to make the over lapping squares but i cant get the right look (ive looked on jsp for examples but cant find any so i made this to show.




the different color squares demonstrating the depth in the squares and how they overlap
but i cannot get right look when i put the image over it..

any directions or help you can give? i tried using drop shadows, some embevelment, but i cant make it look good.