Color Fast Gecko?

When you stop and look, you notice amazing things. This Gecko (I think), turned from a bright green, to a dark brown, then back to a bright green, depending on where he was sitting. I noticed him scamper across the pavement when he was bright green, and sit on a tree that was brown. I kept eating my breakfast, looked up, and he was brown. I went a found my camera, and waited until he jumped onto a green leaf- and took the following sequence over a 1-2 min time period.