It may be tough to identify for a couple of reasons,
1. The photographer that colored the ribbon may not have colored it accurately, just applied colors to make a "representation" of the ribbon.
2. Some ribbons are more than one ribbon sitting next to each other. Again, the photographer may not have applied the colors accurately to designate more than one ribbon.
http://www.wehrmacht-awards.com/related/ribbons/ww2.htm