OK Guys, I don't think I saw this question already answered here or under "Kilt Advice". If so ... sorry.

I've seen flashes in the same tartan as the kilt. Is this as a properly dressesd man would go? Is it tacky?

When wearing solid flashes does one try to match a coulor in the kilt? is it ok to go for a contrast?

I know there are no rules. I just want to know what is accepted as proper for a gentleman.