Can I terminate my rights as a father if I really see no benefit in only paying child support?

No, you cannot terminate or relinquish your rights except in connection with an adoption of the child by someone else. Your belief that Colorado law doesn't allow visitation rights is wrong. Unless a court has found that you are a threat to the child, you can obtain parental rights and responsibilities. The geographic distance will obviously have an impact on how much involvement is practical, but it is possible. If you have not attempted to obtain parenting time rights, you need to do so if you wish to be involved in more than just financial support.