I tried to take some pictures to show what they look like, although it's hard to capture on camera. The first picture shows a refractor (Rua) next to a regular non-refractor chrome card (Herrera). You can see the rainbow effect best on the sides about 1/3 of the way up on the Rua. The entire card refracts as light hits it from different angles. The second picture shows a couple different types of refractors. Some refractors have patterns in them, like the deGrom, which is called a Prism Refractor. Others have colored borders, like the Betances. These days, the regular refractors and some of the patterned refractors might not be numbered, but the colored-border ones usually are. The Betances is #/250. I collect mostly prewar but the shiny stuff can be pretty entertaining sometimes, so long as you don't take it too seriously (like spending $10K+ on a Kris Bryant RC autographed refractor numbered #/5).
