I’ll throw this on the table (and quickly hide my hand behind my back).
It seems that among the countless programmers that like to either get you a monitor tan by throwing at you pure or almost pure white background full screen or push a darker than dark theme, actually only usable in very low ambient light condition, someone exists that understand colours, brightness, hue and contrast.
https://ethanschoonover.com/solarized/
It seems that there is even (cannot say how good) a solarized theme for discourse: