who knew ?google green for max sensitivity in daylight but shifts to blue/500nm as it gets dark.... I usually run at dusk; seems those blue car lights may have more benefits.
irrespective personally went for orange, works good in fog and gives more contrast versus most surroundings, looking like grass/sky in daylight may not be ideal.
the coloured section of the viz jacket is not usually retro-reflective anyway (ie reflecting back car headlights) the retro-reflective bit is colourless for max efficiency - some kind of metallized particles