Good luck. There are a lot of people who are more hung up on their appearance than safety.
If somebody handed me a reflective vest before I was 21 it would go straight into the nearest trash can. I was way too worried about what my friends would think and that they might laugh at me. Most of that silliness went away when I turned 50.
There are still plenty of folks who simply don't realize how hard they are to see on a bike. I rode 50 feet behind a friend wearing black tights and a dark gray jersey on an slightly-foggy overcast day. She blended right into the pavement and the only reason I saw her was because I knew to look for her. A car traveling at the speed limit on that road would not be able to slow in time to avoid rear-ending her. Happily she went shopping and has a few hot pink jerseys that she wears often; and she is upgrading her lights.
Some other friends who are very experienced cyclists don't believe it when I tell them how hard they are to see when they wear their dark non-reflective gear/clothes at night and have a cheap blinkie with a next-to-dead battery. At least I tried.