| Colorado | 
| State of Colorado - Phone Code and Area Codes for Mobile, Whatsapp and Text Messages | 
| Phone and Whatsapp Codes in Colorado / CO - Area Code : 720 Denver suburban | 
| Area Code : 970 Northern, Western | 
| Area Code : 303 Denver suburban | 
| Area Code : 719 Southern, Eastern | 
| US Code List of Codes in USA. Area Code and Phone Information by City and State. |