Anyone willing to make a video test rom? If yes, send me a PM
First image would be Grid of all the colors below on single screen. Color rectangles should be big enough to fill the screen. Order for the grid would be by the number below.
If you pressed Left action Button Grid would be replaced by the first color, in this case Transparent, press button again, then it would display Black, press button again, Medium Green, repeat for all the colors.
If you pressed Right action button it would cycle the other way, i.e. from Grid to White, press button again, now its Gray. Press button again and it Magenta, repeat for all the colors.
If the above is too much work then a rom that makes screen white would be fine too.