The law in Colorado is very strict for underage drinking. If you are under 21 and drive after drinking, you may face very severe penalties.
If you are under 21 and are convicted of a drunk driving offense, your license will be revoked for not less than one year.
If you are under 21 and your BAC is 0.02 or above, then your license will be revoked for:
Three months for first offense;
Six months for second offense;
One year for third or subsequent offense.