Make sure that you haven't enabled a High Contrast theme in the Windows/Mac Accessibility settings.

Make sure that you allow pages to choose their own colors.

• Tools > Options > Content : Fonts & Colors > Colors : [X] "Allow pages to choose their own colors, instead of my selections above"

Note that these settings affect background images.

See also:

• http://kb.mozillazine.org/Website_colors_are_wrong

Thanks Cor-el. I checked all of that. (not high contrast theme, not set to run in 256 colors, not set for "no style" which actually looks way different when clicked .... "no style" will render things even more strange.)

Some more information: I noticed on another website that all of the links are the "default" blue. Remember back in the 1990s when basically all links were blue and underlined? Followed links tended to be purple. Well, there is a website that I visit a lot, and its links are all blue on the problem computer... they should all be black (and in this case, they should stay black even after clicked and followed). Followed links are purple. Again, another CSS error I presume. Is there a way to change Firefox's ability to read CSS files?

1. What about a security setting that disables CSS or something? Or alternative font downloads maybe?

2. is there a way to ignore style type "text/css" either for a security reason or customization?

3. Could javascript be off? There was a menu item for that eons ago I think.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

If images are missing then check that you do not block images from some domains.

• Tap the Alt key or press F10 to show the Menu Bar

Check the permissions for the domain in the currently selected tab in "Tools > Page Info > Permissions"

Check "Tools > Page Info > Media" for blocked images

• Select the first image link and use the cursor Down key to scroll through the list.
• If an image in the list is grayed and "Block Images from..." has a checkmark then remove this checkmark to unblock images from this domain.

Make sure that you do not block (third-party) images, the permissions.default.image pref on the about:config page should be 1.

There are extensions like Adblock Plus (Firefox/Tools > Add-ons > Extensions) and security software (firewall, anti-virus) that can block images and other content.

See also:

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes
• http://kb.mozillazine.org/Images_or_animations_do_not_load
• http://kb.mozillazine.org/Websites_look_wrong

Great ideas. I restarted Firefox each time after a change.

1. Safe mode... same problem
2. Hardware acceleration... off.. same problem
3. Checked permissions.default.image (already 1)
4. Media permissions... all of them say "Use Default" (Allow) except Open Pop-up Windows is "Allow" for Amazon.com

None of that was the culprit. Still blue links everywhere I surf the web... purple followed links. But now I see more ads because my ad blocker is off.

You did make sure that there isn't a high contrast theme selected in Windows like I posted above?

• http://windows.microsoft.com/en-us/windows-vista/make-the-computer-easier-to-see-optimize-visual-display

Yes, I checked. My Vista theme is Windows standard or something like that selected. I don't think it's a customized theme. Definitely never used the high contrast theme... it's a bit over-the-top.

I wonder if there is a way to run a Firefox beta or one of those "portable" executables that doesn't use my user directory/customizations. I could test one of those and see if there is something wrong with the computer itself (like graphics driver or installed software maybe).

It was a weird setting. I fixed it myself, then updated some of the relevant information on the topic myself. Here is the issue:

If the browser.display.use_document_colors user preference in about:config is set to false, background images will not be displayed.

Note that browser.display.use_document_colors is the setting that is toggled via "Allow pages to choose their own colors, instead of my selections above" in my first reply, so if that worked then you may have missed that. That windows in "Options > Content > Colors" also has a button for using system colors.