I think a vest is more than I might want. I carry a hunter orange bandana (fairly heavy cloth, not thin cotton). The darn thing is so bright that it hurts my eyes to look at it. It remains folded up in the bottom of my pack until I need it to function as a signal. (or bandage)
I also often carry a neck gaiter that has an inner orange side.

I'm a big fan of neck insulation in addition to watch cap. I actually sleep year 'round with a simple fleece neck gaiter and I sleep much better because of it.

I prefer to travel subdued but when visibility matters it's good to have options.