Let's see, 6 to 6.5 hours from Canyon (just south of Amarillo) to Colorado Springs, so what, add an hour or so to Denver?
A short back road that saves a mile or two is detailed below. But be warned, it is narrow, two lane, and consists of miles and miles of nothing. But you can speed through most of it.
On 87 north of Amarillo, after you pass the Masterson helium plant, there is a little road (highway 354) that cuts straight west to Channing. There you pick up 385 north and merge with 87 at Hartley.
Channing was the headquarters of the XIT ranch from 1888 to 1911 when the ranch was broken up and sold.