You’re right, this isn’t a sketch or drawing, but Grandpa warrants an exception. Besides, when I do these colorizations, I end up using a lot of the same techniques as I do when I paint digitally.
I know the conventional wisdom is that colorization is unnecessary and usually cheesy, but one of the reasons I enjoy it is that it’s like opening a window into the past. Sure, it’s not perfectly realistic, but it gives me a little impression of what Grandpa looked like about 58 years ago when he got up and went to work. It’s also fun to do the necessary research to get the colors right (no guarantees that I did).