I find the text color on cs.SE hard to read on white background, is there a way to change either the foreground or background color to something else, without resorting to user css scripts? I don't see such options anywhere but maybe they still exist?
Unfortunately, Stack Overflow is the only site on SE that has an alternate color scheme ("dark mode") as a built-in option. There is a request to implement this for the entire network, but it is unknown whether or when this might be implemented.
So, for now, there is no other option than resorting to userscripts. This one, for example, should work on all SE sites.