One of my favorite modern marvels is the absolute electric neon colors now available. These didn't exist 30 years ago.
So one of my beefs is the visibility of bicyclists, especially around dusk. There are no bike lights that can present illumination like automobiles. And automobiles only seem able to see their own kind, especially around dusk. I just had a tandem frame powdercoated in neon yellow. Wow is it bright. But the guy told me he could get glow-in-the-dark powder. I think I might try it out.