I have been working on the garage here at the house. I am replacing the walls and insulating them one at a time as time permits. I am adding plywood panels as I am tired of looking at the studs. I am also rewiring it as I go and raising the ceiling in part of it. Right now I have the back wall cleared of stuff and am thinking about paint. I have an idea of painting it black and then painting some florescent planets and stars on it. I did that to my bedroom when I was in high school.. It was "cool" then but not sure about now lol.
My garage had a real dark paneling when I moved here. I painted the inside of my garage white. Sure helps with visibility.
Once I got my garage all dry walled, I painted the top white and the bottom grey, then added a 1x6 pine center strip painted red - I got the color combo from a photo of Richard Childress's race shop I like your idea of stars and planets, Gene but that is coming from a guy who had a 6 foot high hand painting of National Lampoon's Cheech Wizard on my wall when I was a teen so I "understand"
Another thing I had hand painted on my wall was from a Greenslade album cover - this band used art work from Roger Dean who also did the covers for Yes and Uriah Heep - you might want to do a Roger Dean search for some great art work