You are assuming that Colorado has free and fair elections.
Colorado has only mail-in ballots. You can also use a drop box, which is generally near a library or police station or other government office. If you register with an e-mail address, you will get a message when your ballot is accepted for counting. Is the ballot actually counted? Probably.
The problems are elsewhere.
Colorado (Denver) is US headquarters for Dominion Voting Systems. Colorado uses Dominion systems to count ballots.
Colorado has successfully prosecuted election officials who objected to procedures used in previous elections. It is now against the law in Colorado for officials to make public criticisms of such matters.
Colorado has over 30 counties where there are more registered voters than residents in age ranges eligible to vote, according to census bureau counts.
Denver county has hundreds of addresses where more than ten people are registered as "voters". Many of these addresses are vacant lots. There are similar "anomalies" in other counties.
90% of "new voter registrations" in Jefferson County came from one church and one homeless shelter. Do these people even exist? In any case, those ballots will probably be voted. Democrats excel at harvesting idle ballots.
I do not assume that Colorado has honest elections.