A tenant who withholds rent until repairs are made can be legally evicted for nonpayment of rent. Colorado law does not allow a tenant to make any repairs him or herself and use it as a deduction from the rent.
Except for common areas and multi-unit properties, the landlord is required to repair and maintain the premises only if:
The lease specifies that a landlord is responsible for repairing and maintaining the premises
There is a specific agreement between the landlord and the tenant that the landlord will make specific repairs such as an attachment or a letter of promise