Yes, you can exclude the gain on the sale of a primary residence for Colorado. 

The starting point for your Colorado return is your federal taxable income.  

Adjusting that income for the gain on the sale of a primary residence is not included in the definitions of additions to federal income.  

Additionally, if a portion of your gain is included in your federal income, you may be able to subtract it from your Colorado income.   

The amount you can exclude is up to $100,000.