Steel rim painting
 

sorry can’t post pic yet. Can I paint the inside of my steel rims where the spokes terminate? I’ve taken as much rust off as I could. Or should I leave as is?

You'll have lots of fun taping off 36 spokes each wheel, plus the brake track.
But after you wish you hadn't done the first, you'll be committed to the second. :)

But yes, you can paint rims. I've done it, but I had not yet assembled the wheel, so no taping off of spokes.
I was changing a black rim to blue, and used the "anodizing" spray and base coat available at an auto parts store.
Worked/looked good, and lasted pretty well, too (on aluminum rims)

I would be tempted to do this with a brush. I would even consider one coat of "rusty metal primer" and and a top coat of your chosen color. A disposable "acid brush" would probably work well and no one will see the brush marks or pitting and you can avoid painting over the spokes and nipples. I see no reason that the steel rims cannot be painted.

I always remove any loose rust with a wire brush and give a fresh coat of paint to the insides of steel rims. Standard procedure. Just be ready to clean up any paint that leaks past the spokes onto the primary surface of the rim. I use a rag cut into strips, lightly soaked with solvent and sort of dental floss my way around until I clean up any leak throughs.