add extra row to connect four board image asset

I am currently making a connect four game based on some assets but the images for the board are 7*6 need it to be 7*7 like the actual connect four game. This means that another row needs to be added to the images used to display the board in game. There are two images one black underlay and white overlay and the same two images for smaller screen sizes. I've attached an example of how the 7*6 board was looking like when the two layers came together. In addition there is figma file showing the actual design of the game.