Disable 'Invert Colours' at login

[HelpDeskWarrior]

I have been able to control 'Invert Colours' settings in the Accessibility using a configuration profile and applying it to the computer object. However, Command+Option+F5 and Control+Option+Command+8 both remain operational at the login screen.

Any ideas about how to lock this down?

[plawrence]

@HelpDeskWarrior

Did you ever find a solution for disabling the 'Invert Colours' keyboard shortcut at the login window?

[HelpDeskWarrior]

No, not at this stage.

[russeller]

Hey @HelpDeskWarrior Check out this post https://jamfnation.jamfsoftware.com/discussion.html?id=9981 It talks about disabling Spaces, which uses a keyboard shortcut like invert colors does. Might be a matter of figuring out what key is for invert colors. Also, if users are inverting colors at the login window then you'd have to apply those settings to root. Hope this gets you going in the right direction.

[plawrence]

I looked around and found a few other bits from these sites:
http://krypted.com/mac-os-x/defaults-symbolichotkeys/
http://apple.stackexchange.com/questions/91679/is-there-a-way-to-set-an-application-shortcut-in-the-keyboard-preference-pane-vi
https://groups.google.com/forum/#!topic/macenterprise/dgeruEutsqI

The parameters for the invert colours appears to be 56, 28, 1835008

But I cant find a way to disable these shortcuts at the login window, creating the settings in a plist in /Library/Preferences/ didn't work

@plawrence

[HelpDeskWarrior]

@ssrussell OK, your input is much appreciated. I will check out your suggestions later and report back, as usual, lots going on here that demand my attention :)

[HelpDeskWarrior]

Thanks @plawrence

[russeller]

@plawrence try setting the preference for root under

/private/var/root/Library/Preferences

[plawrence]

@ssrussell

Thanks for the suggestion. I tried putting a com.apple.symbolichotkeys.plist file into /private/var/root/Library/Preferences but the keyboard shortcut still worked. I then noticed that there was a com.apple.universalaccess.plist file in there too, whenever the Invert Colours keyboard shortcut is pressed a value changes in that .plist

<key>whiteOnBlack</key> 
<true/>

I set that to false in the file, but the keyboard shortcut still works. I then tried to make the file 'immutable' so root couldnt update that key with the 'chflags uchg com.apple.universalaccess.plist' command, but sadly the keyboard shortcut still works (even though the contents of the plist dont change) :(

Maybe there is something wrong with the syntax of the com.apple.symbolichotkeys.plist I was using, I'll try and test that out further.

[adminNWA]

Has anyone come up with a solution to this?