The light on Macbook Pros is just the other side of the backlight on the screen. If it was red or green, the screen would also be red or green. This also means

The light on Macbook Pros is just the other side of the backlight on the screen. If it was red or green, the screen would also be red or green. This also means you set the brightness of the screen to zero, then get a torch, shine it through the apple on the back, and see what is on a small portion of the screen.