Ours are white and worn by people who are cold.

Marks & Sparks vest

I never understood why people (OK Americans) wore vests under a shirt even in the hottest climates.

M: 57 / EW: 52
T: 21, M: 8
S: 18, S: 15
Bomb: 1 Jun 14
EA Aug 2014 I think
PA Feb 2015 possibly sooner