I don't understand the given examples

I have several doubts for this problem. I've never played a chess before, but after I checked chess rule here, I still can't understand those things.

• In the case of {"b4", "d4", "f4", "c3", "e3", "g5", "d2"}, "d2" can attack "c3" and "e3", why the number of safe pawns is 6?
• Also in the case of {"b4", "c4", "d4", "e4", "f4", "g4", "e5"}, why the number of safe pawns is 1? I think it should be 4 because there are 3 pawns can attack each other.
• It is mentioned "white pawns" in the problem, but all I can see are yellow ones and blue ones. Which color should be white?

Thank you!