see the following article for suggestions:

Change the fonts and colors websites use

Let us know if it helped.

No. That changes the website font and background colour, I want to know if I can change the highlight colour. Like if I highlight a sentence or a website, it can change to other colour rather than blue (mine's blue).

You can try to adjust the ui.textSelectBackground pref on the about:config page.

• http://kb.mozillazine.org/about:config

• [/questions/936450]

For some reason, my ui.textSelectBackground is not on the about:config. I have a 23.0.1 Firefox and on a Mac just to be sure.

Most of the ui.* prefs do not exist by default (i.e. are hidden) and need to be created, in this case as a string pref.

• http://mxr.mozilla.org/mozilla-central/source/widget/xpwidgets/nsXPLookAndFeel.cpp
• http://mxr.mozilla.org/mozilla-central/source/widget/LookAndFeel.h
• http://mxr.mozilla.org/mozilla-central/source/widget/cocoa/nsLookAndFeel.mm

What am I suppose to do with these three websites you have placed? Do I copy and paste them to about:config or... If I am suppose to create them, how can I do that? Sorry for questions that sounds silly, I'm a new at this and learning more.

You simply go to about:config. Right click on the page. New>String. On the name, write ui.textSelectBackground . Then on the next field write the name of your color as green, black, etc and for the rainbow use sites like, html-color-codes.info for the color code. eg. #428E57.

Go to the Mozilla Add-ons Web Page. There are several add-ons that will change colors for you. You can even make one site have different colors or the same as another site . Also, check out Firefox Options > Content. And select Colors.