GLCD component on Raspberry Pi wrong colours

[rotaxmax55]

I am using the component GLCD_RPI to run the standard RPI 7" touchscreen LCD on a RPi 4B.

I am able to create displays using FC10 but the colours are wrong unless they are black or white which both work.

If I set the background_colour to mid grey, 7F7F7F, I actually get a light blue background, looks like red is missing from the display.

This is with the colour_bit_depth set to 24 and red_bit_depth, green_bit_depth and blue_bit_depth all set to 8 which is how the component started.

I know that displays do not always use 8 bits per colour so are these settings wrong?

The display works correctly when it runs the desktop so there is no physical problem with it.

Any pointers please.