South Denver, CO. March 20, 2016. Approximately 11:45AM. My wife and I were driving northbound on I-25 from Colorado Springs to Denver. The sighting happened somewhere between CO 470 and Yale Ave on I-25 North. What made us notice the two objects is they were bigger than other commercial aircraft flying over the interstate and they stopped, hovered, changed color and then disappeared. We saw two flat, white discs (or more likely could have been white cigar shaped, we were looking at them edge on - definitely not saucer or domed shaped or triangle, etc.). They seemed to be moving at the same low altitude, speed and direction as commercial airliners flying out of DIA over downtown Denver - but they had no wings and were at least about twice the size of a commercial airliner. One was a good 2 to 5 miles ahead of us to the North and the second one was probably another 5 miles North of that one. They were moving and then suddenly stopped over I-25, to the NW of us, hovered in place for about 30 seconds and then began to turn a reddish orange color, slowly becoming more and more transparent with the blue sky - and then poof! Gone! They disappeared! My mileage distance is a big guess, I'm not in aeronautics and am not a good judge of aerial distances. The feeling initially was "Oh, that's a strange plane, looks bigger than the others.." to "Oh my! Two of them stopped! Those are not planes!" My wife doesn't really buy into the UFO thing and it made her so uncomfortable she didn't want to discuss it with me. I kept trying to talk about it and discuss it, but the shock of it all was very obvious and unsettling to her. It all happened in under a minute and we were driving at 80 mph, so unfortunately we didn't get any pictures or video of it. I know anyone else driving with us on I-25 going northbound saw it if they looked up into the sky.