Illustration of a strange cowboy

This illustration is both an exercise on colorization, and a character design exercise coming from a private joke for the mascot of the company Virtual Rangers, in which I work.
I first draw the black and white version and try to create a hot/cold contrast with the colors but I'm not very satisfied with it, maybe I should have done the environment only in yellow/orange teints (including the sky). If you have tips or suggestions for this colorization, don't hesitate to leave a comment !