This is mostly aimed at night-time reading and is an extension of f.lux but on linux you can apply custom glsl scripts to the screen with the compton compositor. I invert the screen and then highly red-tint it. This way I get 'native' darkmode on everything black-on-white, without having to depend on developers making a dark mode, buggy userscripts, and it works on all applications, even videos. (https://github.com/JZL/linux-color-inversion)

I have a script which changes my terminal and texteditor colorscheme then calls this script