C.R.S. § 38-12-701

(1) Notwithstanding any other law, in a nonresidential tenancy of one month or longer but less than six months in which there is no written agreement between the landlord and tenant, a landlord may increase the rent only upon at least twenty-one days’ notice to the tenant. (2) Intentionally left blank —Ed. (a) Notwithstanding any other law, in a residential tenancy in which there is no written agreement between the landlord and tenant, a landlord may increase the rent only upon at least sixty days’ written notice to the tenant. (b) A landlord may not terminate a residential tenancy in which there is no written agreement by serving a tenant with a notice to quit pursuant to section 13-40-107 with the primary purpose of increasing a tenant’s rent in a manner inconsistent with this section.