I think it is possible to ascend that colouir. Maybe 30 degree angle. If I remember correctly there are large rock cliffs to the right of the colouir but no serious rock within it. Several years ago a climber fell from about 2/3 of the way up that chute and ended up pretty beaten up. Dislocated shoulder amoung other injuries. Some other hikers and myself helped him walk out and I took him to the hospital in Long Pine.
Make sure you know how to self arrest. 30 degree slopes can be dangerous if they are hard or icy. And the run out at the bottom of this chute is full of car size boulders. If you feel comfortable....go for it.