The Libero in Volleyball is like a GoalKeeper in Soccer, The Libero is the most skilled defender in Volleyball. And in the rules of volleyball the Libero must wear a contrasting outfit to the team
If you mean that someone is wearing a different color that is because there is a player called a Libero who is a defensive specialist that can come in and out of the game for defensive purposes but does not count as a substitution. They wear a contrasting color top to distinguish themselves from the rest of the players.
The person with the different colored shirt is usually the best defensive player on the team, and us called the libero.
blue jeans
black, white, or dark blue if you're awesome
You can really wear almost any color since it's such a neutral color, except other neutral colors! I recommend pink
blue flats
Orange pants? Uh.. you maybe should where a different color of pants, black or white are the only real colors that will match, unless your favorite sports team has orange, then you can get a shirt with their color that will match. :D
The goal keeper must wear a jersey distinguishable from his team and the opposing team. This is almost always interpreted to mean he must wear a different color.
Tree Top Piru is typically associated with the color red, as it is a set of the Bloods street gang.
D.S.' are treated as regular players in terms of rotations and rules. They are subbed in when a front row player gets to the back row, then back out when the DS gets to the front row. A libero is a special player with the same skills as a DS, but has a slightly different set of rules. Liberos can sub an unlimited amount of times, and in some leagues, cannot serve. (though this is uncommon) Liberos also cannot set a front row player in front or on the attack line, nor can they attack when the ball is over the top of the net. In short words, A DS costs the team a substitution and can only go in for one position (one person). A Libero can go in for any person so long as they are back row. Liberos can also serve now, but only in one position.
none. you should wear no top.
depends on what colour your pants are