IMac – Yellow pattern all over application windows

I've had an identical problem on my 2010 MBP since upgrading to Lion last fall. Here's what I did today that seemed to fix the problem:

1) Go into Macintosh HD and find /Library/colorsync/profiles/displays
2) Move all files in the 'displays' directory into a backup folder on your Desktop
3) Open System Preferences > Displays and click on "Color" for each of your displays
4) Your computer will take a few seconds and create a fresh display file for each monitor.

After doing this all the weird screen artifacts and colors have gone away on both my MBP LCD display and my 19" external monitor connected with mini-DVI.

If you enable full keyboard access in System Preferences, you can press tab to select the buttons.

I don't know how to focus the windows though. They can't be selected with ⌃F4 or ^F6. I was going to suggest Witch, but it doesn't show them either.

This is a bit of a hack, but you could assign a shortcut to a script like this:

tell application "System Events"
    repeat with p in {"SecurityAgent", "CoreServicesUIAgent", "loginwindow"}
        if exists process p then
            tell process p
                if windows is not {} then
                    set frontmost to true
                    exit repeat
                end if
            end tell
        end if
    end repeat
end tell

Password dialogs are shown by SecurityAgent, Gatekeeper and quarantine dialogs by CoreServicesUIAgent, and the force quit window by loginwindow.