In the last few days, i've seen a few threads on here where people are suggesting legislation of cycling - again fundamentally to legislate en masse like that, you'd need a way of identifying people, then you'd need registration, licenses, COT's, etc etc - meaning even less cyclists on the road, and even less notice taken of us no matter what we are wearing. To be honest, most cagers don't look, because if they get into an accident it isn't going to hurt them, they feel safe in their bubble and that makes them careless. They also often aren't concentrating, because sitting in the bubble, the nice man on radio 4 is much more interesting than whats happening around us.
It's different on a motorcycle or bike, we are responsible for our own safety - I admit it, I wear mostly black. It has reflective flashes, and if i cycle at night (rare) i use several lights, and apparently make quite a sight as the reflective flashes flit by. I also wear red gloves. I don't ride much in traffic or on busy roads, i do wear hi viz backed gloves, I also command large road presence, partly by being a large person (too large) and partly because of aggressive road positioning.
I accept 100% that this doesn't work on bicycles in traffic, and while i do ride the motorbike into central london, i don't ride my bike.
It's an interesting point though, i've never chosen cycling clothing because of colour or reflection, mainly buying technical clothing, end of line, so better on price, thats in my size, which so far happens to be mostly black or dark blue (certainly in winter tights and jackets) now i have the ebike and seem to be riding into the winter, it might be time for a bit more hi-viz.
For reference my motorbike gear is also black with reflective stripes and flashes. For cycles I buy what fits, is comfortable, performs well and is cheap. For the motorbike i buy whatever has the most armour and resistance.
These days i ride everything defensively (fnar!), I used to be bold, now i'm old