No shelves and I like the oran ge wall but maybe a blue would work really without seeing his space how would we know.

I like your idea of shelving. I dislike accent walls, so I would paint the same color as the other walls. I think you might find it helps to visually expand the space.

My take on small amount shown: orange nice cause of the silvery frames, etc... and it's warm just like the wood. Posting cause had it open:

Nourison Celestial Sealife Area Rug, 7'10"x10'6" · More Info

Show the furniture? does climate/ sun exposure make you want more heat, or cooler?

I like your rugs, but as you know it doesn't have to match the paint. I even like the squiggly lines, neutral.

Mohawk Home Huxley 8'x10' Rug, Adobe · More Info

Q - does he like brights more, or earthy more? showing rugs imo should help discussion.... or post his art, etc...

Diamond Illusion Multi Rug, 5'x8' · More Info

Maybe this color blue? =)

What color are the fabrics and textiles in your condo? That's where you'll find the accent color for the orange wall.

If that first multicolored rug that everdebz posted were a wallpaper I would use it in place of the orange. If this were my space I would either find a similar wallpaper or paint the wall in the same design