Make the panels one color

I'm currently challenging myself with "Game a Week".

For the 28th week, I created a game where the goal is to make all the panels the same color.

There are white and black panels in the game.

Actually, the color of these panels can be changed.

By pressing the buttons at the bottom of the screen, white panels turn black, and black panels turn white.

However, I’ve forgotten which button changes the color of which panel.

It’s hard to tell when the panels are all mixed up, so please make them all white.

Once all the panels are white, the game is clear.

Controls:

Pressing a button will change the color of the panel corresponding to that button.