You literally typed it out right here. Good lord it's on the same page. Also, below is straight from the Colorado SOS page. Just like I typed, all registered voters receive a ballot in the mail.
Q1. How do I receive my mail ballot?
A1. Every voter receives a mail ballot. The ballot will be sent to the mailing address you provided for your voter registration file. To check the address on file, or to make any changes to your voter registration visit
www.GoVoteColorado.gov.
If you prefer to vote at the polls, you can vote in-person at a voter service and polling center. Please visit
www.GoVoteColorado.gov to find your polling locations.