I have found that a polo shirt is best at work with a solid colour kilt. I wore my first kilt around the house long enough to be comfortable with it on as if it was natural to me. The first time at work, I had forgotten that I had on a kilt. Got surprised by a few compliments. Much easier today than when many years ago I wore my kilt to school.
That said any UK looks good with a polo shirt of solid or design. I wear a solid long sleeve shirt with any of my Tartan kilts (see my avatar) and am noticed for the confidence I have in myself to pull it off. ( Bigger bonus checque this year.)
--- Steve