I bet if you were to go to your LHBS and ask if you could taste some, they would let you put a couple grains in your mouth and chew on them to see what flavors they contribute.
Different levels of crystal will get you different flavors (and colors) depending on how dark they are. American crystal malts usually range from 20L to 120L. 20L is the lightest and has a sweet slightly dark sugary flavor. 40L and 60L I think have the most pronounced caramel flavors, 60L being a little stronger than 40L. Anything over 80L and you start getting more complex flavors like dark fruits (plum, raisin) and rich sweet caramel flavor. 120L gives a very noticeable almost burnt sugar flavor, a dark sweet aroma, and some deep red hues to the beer.