C.R.S. § 18-16-103: Purchaser to identify seller.

(1) No purchaser shall purchase any valuable article without first securing adequate identification from the seller. The type and kind of identification shall be limited to the following:

(a) A valid Colorado driver's license;

(b) An identification card issued in accordance with section 42-2-302, C.R.S.;

(c) A valid driver's license, containing a picture, issued by another state;

(d) A military identification card;

(e) A valid passport;

(f) An alien registration card; or

(g) A nonpicture identification document issued by a state or federal government entity if the purchaser also obtains a clear imprint of the seller's right index finger.