1. Open TextEdit, make the document plain-text, and copy this:
Code:
* {color: black; background: white;}
2. Save it as
blackonwhite.css or whatever
3. Navigate to Safari, Preferences, Advanced and under Style Sheet select your newly created blackonwhite.css
4. Refresh the page.
Moving to other tabs will "ottomatically" change them to black text on a white background. It appears that Safari caches this document. If you want to mess with the style sheet you'd need to save it and reselect it (deselect then select again) in the Safari Preferences.
Doesn't work when I tried to change anchors so if they are bright yellow they will look weird. Hope this helps.