It just looks different because of lighting. As Alidar says, it's the same suit in a pic taken last year.
Mahershala Ali, from The 4400, where he went by his old name Mahershalalhashbaz Ali, House of Cards, and both The Hunger Games: Mockingjay movies, has been cast as comic book villain Cornell Stokes aka Cottonmouth.
Scott Glenn returning as Stick. Something I just realized... There has been no word one way or the other as to whether or not Vincent D'onofrio is returning for S2, even if only in a limited capacity.
You're right. I'm expecting/hoping he will pop up in some capacity. Maybe they'll just try to save him for a surprise guest spot part way through the season.
The season 2 trailer has dropped, although eagle-eyed viewers will note that the first 90-odd seconds are all from S1.
Yeah, the actual Season 2 footage is just the last few seconds of the trailer, but it is a pretty great last few seconds.
Who was that guy Stick was talking to at the end of his episode - the bare chested guy in the dark, smoky room?
I have seen it theorized that it is Iron Fist, though that is speculation. I don't think it has ever been confirmed.
It's clearly Stone. Google Image Search Stone and The Man Without Fear and you'll see it's a literal recreation of the shot from the comic.
I'm thinking The Hand, at least, seems pretty likely. I think there were some hints pointing towards them in the episode with Stick, and the presence of Elektra, who is connected to them, makes me think we'll be seeing them some time soon.