If your dad is uncomfortable with computers, why not just have him draw
and color a piece of art before scanning it?
That's what my artist friend and I did for a contest:
You'll still have to touch up the art yourself, as the programmer, to do things like cutting out the transparent parts, and softening the edges, and so on.
I've also done the way where the artist draws line art, and I digitally color it in. That also works, but is alot more difficult and time consuming if (A) the artist isn't familiar and (B) you aren't familiar. It'll take alot of work to learn that
different skillset.
Digital art and traditional art are related, but different, skills. It makes much more sense in your situation to have him do what he normally does, and you scan it and do rudimentary editing, then for him to learn an entirely new skill.
One thing that is nice, though, is this: Take a look at the mice here.
The three mice on their hind legs? All are the same mouse.
My artist friend sketched the rough outlines for the entire basic mouse animation, I scanned the art and then reprinted the work on multiple different sheets on watercolor paper, and then she drew additional unique details (like their clothes, fur patterns, and weapons) on each one and watercolored each one individually.
(
the sketch of the sniper laying on the ground was a unique one we only used once, the other sketches were used as a base for all the meese)
This saved a huge amount of work, because, for her, the pencil-work is half the labor. I also digitally tweaked the color of one (the sniper), after the fact, to easily create a four mouse (the rifleman; top-right).
Digitally coloring it from scratch is painful if you don't already have that skillset. I tried doing that in a prior competition and the results were sub-par and time-consuming. The most difficult part was the texturing was too flat because I didn't have the time to properly shade the body - it would take me several hours to color it, and it'd still not be all that great.
It's far easily for me, as the programmer, to learn how to digitally clean up some already good-looking art, then for me or the artist, to learn from scratch how to digitally color
in a quality way lineart.