Tangerine is not in my vocabulary for colours. Pink is close enough, but now that I look closer it looks kinda like orange. Doesn't change my opinion though.
I don't think I've ever heard anyone call a colour tangerine before. We call that orange over here.
That waistcoat should be worn with dark tweed or flannel suits, with wool ties in rustic colours. It has no place with a light jacket and trousers.