[FMadera]

The libero player only has to have a jersey color contrasting to the non-libero team members. Multiple liberos are not required to have the same libero color, they only need to have a color that contrasts non-libero players.

In addition, if the team was wearing dark blue, the same libero player can play set one in white, go to the locker room, change, play set two in yellow, go to the locker room, play set three in neon green, etc, so long as the number matches his/her number on the roster. Heck, all the players can change each set so long as the contrasts match and the roster numbers match.

As was stated, generally, as long as there's not a rule making it illegal, it's legal.