Need help picking waistcoat colour pattern

[highland mafia]

I'm putting together an outfit for solo piping day completions. Brown brogues, Lovat green hose, purplely flashes, isle of Skye box pleat kilt, brown sporran, white shirt, purple tie.... Now what colour waistcoat?? I've thought about a browny tweed. But I think it might be a bit too brown with the sporran and shoes. What about a grey waistcoat?? Or a greeny colour?? Again with green I wonder if might be a bit too much green.. I don't normally wear a jacket when competing. So just the waistcoat and shirt sleeves.