In Pokémon Black 2 and White 2, Team Plasma is broken into two different forces, each with different purposes. One force still vows to release all Pokémon from their Trainers. The other one, with Ghetsis as the leader of the newer force, which intends to take over Unova. Colress serves as the acting leader, but is also subserviant to Ghetsis.
1) Team Plasma's Goal is to freeze the whole Unova region with Kyurem and use the DNA Splicers to fuse Kyurem and Zekrom (B2) or Reshiram (W2). With this, they think they can
become the most powerful people in the world. On the other side, N and some sages are opposing them, as they learnt that the ways of New Team Plasma are wrong.
2) Colress is a professor who is helping New Team Plasma with machines and all the technical things like the place where Kyurem sits in the Frigate. He later battles the player and gives a Masterball after gathering himself together. His goal is to draw out the strength of Pokemon.
3) The weird blue thing is just a design the GameFreeak designed. It makes him look more like a professor on the dark and evil side. It can be an Articuno feather or a hair draw, it's up to you what you believe.