Well, it can be pink or beige, but that's just because of iron content. When they're below the surface you can't clean them without destroying the crystal itself unless there remains a channel or entryway from the outside. To my eye, the deeper the blue-green the color in the crystal the more greenish it often tends to look. Crystals can go from pale blue to sky blue to dark blue to very dark blue-green. I've seen good stuff from Russia, Africa, and Amelia, Virginia.
Brazil seems to be the place where monster crystals of all sorts come from.
Most of the Colorado material forms in the Pike's Peak granite batholith at various well-crystallized places. The most famous is Crystal Peak. This is a huge area. The downside is that considerable quantity of the land was developed into cabin and home areas some years ago. Rockhounds have not always left a good impression on the local residents.