Accent walls are usually my pet peeve, but in this case, I think it could work and add some drama to an otherwise bizzare wall. I would do the entire wall, not just a column. Floor to ceiling all the way across. You kind of have to go big for this look to feel right.

I like the idea of just the center section as a painted accent wall...to draw the eye away from the busy angles in all those openings. Just tape a paint line.

This is a concept render for you. See how the eye focuses on the dark accent wall.

Whole wall. Floor to ceiling. Love that color too.

He can always paint one column, live with it for a while and decide whether or not to paint the rest. (I still vote for whole wall though.)

I agree, whole wall, floor to ceiling.