There have been many studies on colors and if they help make you show up.  Fire Department for their trucks, Southern Pacific Rail Road, California Transportation and Highway maintenance, to name a few.

That yellowish green color with reflective strips work the best,

Red and orange; turn dark to black in low light or at night.

White blends in and gets washed out in bright light.

Southern Pacific and Cal Trans will not let you within 50 feet (literally) of their tracks or road work sites with out the yellowish green vest with 1” reflective strips on. I forget the exact numbers but the drop in workers getting hit was very dramatic. Something like; incidence rate dropped from 100 per 10 thousand to like 2 per 10 thousand.

So to answer your question; wearing a safety vest is of great help. The very small and discreet reflective ribbing some jackets have, are of some help but not much.

Gfurlo

In my opinion (and this has nothing to do with the study) too much emphasis is placed on passive visibility measures, such as high-viz gear, and not enough on active visibility measures, such as adjusting speed and position to improve sightlines between the rider and potential threats.

I've tried Helmet Halos, retro-reflective vests and super bright Solas reflective tape all with a slightly noticeable effect, particularly in heavy traffic.  Even a little bit helps!

I doubt you can ever win an argument with a larger vehicle so don't even try. 

Ray Nielsen, in Minneapolis and never been in a collision in 59 years of riding.  Tipped her over once or twice (okay three times) though.