He's getting darker!

[WorldClassFrogCoddler]

I hope you will keep us updated on FDR. I've never seen such a dramatic change!

[GrifTheGreat]

Its in response to the environment. They will darken to blend in. Coconut Fiber substrate usually causes the frog to darken and try to match the dirt.

As for that odd posturing. It could be a defensive position in reaction to you photographing him, but I'd like to see an updated picture of him sitting on a flat surface just to be sure. As Corlos said, eating well is a sign of a happy healthy frog, but need to be sure something else isn't apparent.