What colour hose and flashes would work best?

[Jock Scot]

No, don't mind at all but I but I still don't like to mix any tartan as a general rule. To me it looks slightly unco-ordinated even though it is acceptable

That's the thing though, Highland wear, the kilt and its attire, almost goes out of its way not to co-ordinate things, or at the very best, not to give it too much thought.