Yes, but only in very specific circumstances. An annulment, or declaration of invalidity of marriage as it is called in Colorado, most likely will not be any easier for you to obtain than a divorce. The outcomes are essentially the same; the only distinction is that if your marriage is annulled, it is considered never to have happened in the eyes of the law. Depending on how long you were with your ex, getting an annulment may still involve dealing with such issues as property division and child support.
In order to have your marriage declared invalid in Colorado, you will have to prove that a specific legal circumstance existed. According to the 21st Judicial District County and District Court, examples include:
Your marriage was against the law because you or your spouse were already married to someone else.
The marriage was based on a dare or caused by force.
You did not get your parent's permission and you were underage.
You were defrauded or deceived by the other person.
Physical consummation of the marriage is not possible and this was unknown to you.
Your marriage may also be eligible for annulment if you can show that you were under the influence of drugs or alcohol at the time of the marriage, or you had a medical condition. You will need to show that this created a state of diminished mental capacity.
So while it is possible to have your marriage declared invalid in Colorado, it will not necessarily be any easier or less expensive than getting a divorce. This is intended as general information on this topic and should not be construed as legal advice.