I started the game, loaded the Synthetic court, went back to menus, then loaded the Clay court and it was alright. Are you sure if you do that on your side, the Clay court is green ?
I got your log, and it seems you actually switched the 2D Background from on to off after have loaded an indoor court and switched to the clay, which seems impossible because normally when you apply the change, it should reload the current stadium, so I'm not sure what you did exactly...
Anyway, I tried to redo that, but the clay court still loaded correctly. Could you tell me exactly what steps you do to get to that wrong surface..?