In the scene that introduced the new M, she made references to the relationship Bond had with her predecessor, and how his womanizing ways are common knowledge. He's obviously known by Moneypenny and Q (the latter of whom is the same actor).

So the possibilities are:

1. He's the same Bond.

2. He's a long-established MI6 agent who just inherited the role of Bond.

3. He's an established Bond, but in a continuity we haven't seen up to this point (ie. he's had previous Bond adventures, but we never saw them).

But he's very definitely not "green."