1 Colo. Code Regs. § 205-1, Regulation 44-20-121(3)(k)
All motor vehicle dealers and all used motor vehicle dealers must be open for business at least three (3) days per week for a continuous period of time not less than four (4) hours per day between the hours of 8 a.m. and 9 p.m.
Any dealership open less than forty (40) hours a week must post a clear and legible sign on its place of business indicating the days and hours that it is open for business. In addition such dealerships shall notify the Board in writing of any subsequent change in such periods of time.
Any dealership which will not be open for business for a period of at least two (2) weeks must post a clear and legible sign on its place of business indicating this fact as well as notifying the Board in writing of such fact.
A dealer's principal place of business shall be made available to inspection by the Board or its agents and employees at any reasonable time even if such time is outside the usual business hours posted by the dealer.
1 CCR 205-1, Regulation 44-20-121(3)(k)