Why does my Cd have a rainbow?

[Duendelox]

Im sorry for being a "Noob-Ster" but I haven't been able to figure out what it means, or if its of any importance to leveling it up.

Its a bronze classical Cd.

 

[Duendelox]

Nevermind, I think I get it now. Sorry for the blonde moment Lol.

♥