I've got a very elegant black lo-vis jacket.
It seems to get me far more attention than the yellow thing I keep in the luggage bay for those rare occasions...
I think there's a rudimentary colour code - yellow seems to be aviation, orange railway, but that's as far as I've got. We could make life so much brighter by having a full spectrum of hi-viz colours for different purposes.
Er ... this is Jet Blast, innit?