G&M propose a route for Colony Baldy that utilizes the Rainbow Trail to the Macey Lakes Trail, takes you up to one of the higher, southern lakes, gains a saddle west of the Colony Baldy summit, then finishes with a ridge walk east to the summit. We won't argue the factors that make this a good route. It has the advantage of more trail access and an opportunity to visit the beautifully set Macey Lakes. The main advantage our route has is a more direct approach thus reducing the overall mileage and time a little. The main disadvantage is the required bushwhack.
From the trailhead, take the path that leads SW and connects with the Rainbow Trail #1336 in just under one-half mile. Cross Horn Creek on a handy bridge and follow the Rainbow Trail south to the Macey Lakes Trail #1341, another 2.6 miles, crossing minor drainages and rounding various ridges. Cross Macey Creek on another good bridge and continue on the Rainbow Trail another 2000 feet with some uphill gain to where it contours around the northern branch of the NE ridge of Colony Baldy. Use these approximate coordinates: N 38° 01' 21" W 105° 31' 58" elevation 10,200 ft. Most all of the hiking to this point is forested. It will take a little over an hour to reach this point. Mountain bikes are allowed on the Rainbow trail. We turned off the trail in an area of lodgepole timber where the trail makes a turn to the south.
Head up the forested NE ridge of Colony Baldy. In 1995, we did not find this bushwhack to be too bad, however, pine beetle kill may have altered that to some degree. Besides game trails through here, there's also evidence of human trails. Usually it's best to try to stay on the ridge crest. Once you reach treeline, you can either continue on the ridge or follow game trails over to the left into a gully. The choice doesn't matter much. On our way up we saw a large group of bighorn sheep and several ptarmigan. The hiking will be on mostly tundra. As you gain elevation, the tundra becomes more sparse with smaller, embedded rocks and small talus. It's generally easy hiking to the summit with a couple of false-summits along the long ridge. It took us 4:20 to arrive at this summit from the trailhead with our kids in tow. On this particular climb,we had to contend with steady winds of 40 mph and gusts approaching hurricane force that would almost knock us over. Typical Sangre de Cristo conditions!
The view from the top of Colony Baldy is certainly worth the effort with the entire Crestone group of peaks visible to the SW. The rugged spires and dramatic cliffs are quite impressive from this vantage point. Return as you came unless you want the additional mileage, in which case, you could descend the west ridge and drop down to the Macey Lakes to pick up that trail which will lead back to the Rainbow Trail.