You can google "3m reflecting tape" and get a bunch of hits. I did that perhaps 10 years ago. Bought 3" white tape suitable for fabrics and put a lot of it on the back, sides and bottom of my day pack. Haven't touched it since and it still works (very well) and looks good. The pack has seen a lot of use and the tape zero consideration. The company was an industrial supply outfit. My google showed a few. This one had the tape I wanted and an amount I could handle.
My searches have also come across a chart of colors vs % light reflected; ie how "bright" they are. White being the best and yellow very close. My rain bike got painted the standard sky blue powdercoat, The 3M blue is that exact color. I have 10' of 1" blue tape on the bike. (I didn't know how close the tape would be when I ordered. I was very pleasantly surprised. Daytime you can barely see it. At night, the bike is very visible. Not bright; it is the low reflecting blue, but there is so much the bike is very visible.
Ben