[Excerpts from online regulations]
Article IV, Manner of Taking Wildlife, #004, part 3 Other Aids
A. “Mechanical calls may be used to take all species of wildlife during established seasons.”
B. “Electronic calls may be used as an aid in taking furbearers only.”
C. “Decoys may be used.”

Chapter 3, Furbearers, Game Reptiles and Small Game except Migratory Birds
“The following are legal methods of take for small game species listed in this chapter. Any method of take not listed herein shall be prohibited, except as otherwise provided Statute or Commission…Artificial decoys and calls, except recorded amplified calls or sounds; for turkey.”

Part E. Furbearers
“Electronic call devices, during legal hunting hours.”

B. "Furbearers" means those species with fur having commercial value and which provide opportunities for sport harvest including mink, pine marten, badger, red fox, striped skunk, beaver, muskrat, coyote, bobcat, and raccoon.

[Overview]
Colorado permits use of electronic wildlife callers for furbearers. The restrictions for the use of electronic or mechanical decoys are on crow, turkey, migratory game birds, deer, and elk.