Screen Inversion - Except for images and video?

[Coolnat2004]

My grandma just made the switch from Windows XP to Mac, and she has some eyesight problems and can only read text when it is white-on-black. I have turned on the system preferences option, but this is also inverting the UI and any photos she may be looking at. Apparently, this option in Windows does not invert images and video.

I tried to teach her the key combination to switch back and forth to no avail. Does anyone know of an application that will selectively invert the screen, allowing images to be in true color, but virtually everything else be inverted?

 

[GGJstudios]

Did you try Option-Control-Command-8 ? Or is that what you're saying you tried and it doesn't give you what you want?

 

[Coolnat2004]

Did you try Option-Control-Command-8 ? Or is that what you're saying you tried and it doesn't give you what you want?

That is what I have tried. She doesn't like that the photos are inverted, too, and she doesn't get that she can switch back and forth on demand.

 

[angelwatt]

I think I've seen a browser add-on for Firefox that helps with accessibility that might be of help. I'll see if I can find it.

If the keyboard combo is hard for her to remember, you can change what keys are used,
System Preferences > Keyboard > Keyboard Shortcuts > Universal Access.

Edit:
For Firefox
https://addons.mozilla.org/en-US/firefox/addon/10403/ (not mozilla reviewed though)
https://addons.mozilla.org/en-US/firefox/addon/4242/