Wow guys thanks alot for all the replies and a happy new year! I had originally wanted to do the entire building inside with steel paneling the same color as the exterior but drywall was a more reasonable option. Plus I had fears of an echo chamber with the steel. So I've decided on a very light gloss grey. All my outlets and switches are grey. My prior profession as a bodyman/painter hasn't left me..lol.. So I picked up an autobody prep station to help with the fume evac. its going to get put in a corner. Needs some curtains but hopefully help with most of the fumes and overspray. Here's some photos of the building. It started out life as a basic pole barn with 2" insulation and vapor barrier. Then we framed it up, added more insulation and another vapor barrier then drywall. Its been a multi year project but hopefully some light at the end of the tunnel! HAPPY NEW YEAR!