Bill, I think that hose between a rust and pumpkin color would look great with tartan flashes (in your case). I believe you could get away with mustard and burgundy also. These colors would depend on the event and how much attention you want to attract.

I actually wear elastic garters to keep my hose up (when kilted) and my solid red flashes are attached. Until I expand my hose color collection (to match the growing variety of kilts) I'll stick with just the one set of flashes for now.