There is CD media of other colors, either on the market or in research labs. One of those which appeared some time ago is the red media. This media, as any other that is not silver, gold, blue or green is nothing but one those four conventional colors with dye or different metallic alloy and even the result of a combination of dyes and a non-conventional metallic alloy at the same time.
Because they are rare, these CDs have gone through few analysis, but seem to be of inferior quality, mainly because they use dyes! Some manufacturers test copper-based alloys in substitution to aluminum in the silver CDs, what results an orange or even red CD, but basically has the same characteristics of the low quality silver CDs, but with higher durability and reflectivity that allows them to be easily read in different drives.