The 28-year-old Jamaican international scored 14 goals last season and caught the eye of the Midlanders.
"Aston Villa contacted us a few weeks ago with interest to see Omar up close," Rapids managing director Jeff Plush confirmed.
"After discussing the opportunity with Omar, we felt it would be a good chance for him to get a leg up on pre-season training and at the same time get the experience of training with a Premier League club.
"Omar is a Colorado Rapids player. We explained to Aston Villa that we would be open to discussing a loan agreement for Omar until our season starts on March 19 if it benefited Omar and the Colorado Rapids."
Plush insisted that Colorado were not looking to sell their star striker, adding: "It would take Aston Villa or any club making a significant offer for us to even consider transferring Omar."