Oled screens question

Hi all, i was looking everywhere and couldn't find red oled display. Is there any good reason they don't make 0.96" or 1.3" oleds in other colours than white, yellow/ blue? I have seen red ones but they are bigger. Also i think that wouldn't be so hard to make different monochrome colour as they make even colour ones.

It's probably just the lack of demand for red, green or other monochrome versions. White and blue are 'the thing' at the moment. The blue with the yellow band is nice because you can make a distinct status bar (or whatever) on your display.