If you are a nonresident service member on active duty, your vehicle is exempt from the Colorado specific ownership tax. You have to be the owner or co-owner of the vehicle.
Complete Form DR 2667, the Nonresidence and Military Service Exemption from Specific Ownership Tax Affidavit, and submit it when you register a newly purchased vehicle or renew your registration.
Form DR 2667, your military ID or orders showing active duty status, and proof you are not a Colorado resident.