The changing colours on the board is a quite interesting set up. They correspond to the positional advantage white has on the board only, as opposed to the balance of the position on the board for both players.
A green square would suggest white has sufficient control of the square it can control, whilst a red square would suggest the square is controlled more by black. The darker the shade of square would suggest the more, or less control of the square white has in that given position compared to other squares.
A clear square would suggest white does not currently have any influence on the square in the current position.
Maybe it would of been better to set the positional analysis against the black pieces to see its positional advantages or disadvantages instead over the course of the game.
The natural language the programme is using is great but it can only take you so far along the path of a game.