Ask yourself if you're so desperately in love with Chrome/Chome-Clones that you cannot fill your other important need in Firefox. (After all rumor is it they are moving more towards Chrome in UI!)
In the Browser Wars, back when I just stopped being a Newbie, I had to pick a browser, and for all its minor faults about memory usage etc, FF/related won hands down for being the most extendable for "rare" custom needs like yours.
The crux is there is a key setting in FF that you *uncheck* that says roughly "allow page to pick its colors". To me that seems the key #1 to what you need. Then Key #2 is that a "Windows theme" is pre-picked, but *you make your own and save it somewhere*. Just to avoid a wall of text, I'll stop there and stay simple and post some screen shots to suggest my idea.
In my quick test, at no time (With Caveats! Ask me about C&C!) when "all the horsepower is turned on" did a truly "white" page appear while loading, which paraphrasing a software engineering spec "is what I think the requirement was".
Then the point is you have TWO themes (or three!?) and when you "want to turn off the lights" you switch on "Dark" and when you can handle the white you switch it back.
My rough point is it sounds like your light needs are pretty serious so some of the eyecandy seriously drops off, but that can only make nothing but sense if you view a special form of a website that isn't what the designer thought about. But if the text is there, and the links work, then I think you might "settle for a draw".
In my rough concept:
DCInverse filter for white windows
SlashdotInverse filter for white windows
Chessbase (with a medium light popup)Inverse filter for white windows