I work in IT at a middle school, and have found that in the computer labs, the students have figured out how to turn on accessibility options using keyboard shortcuts. Unfortunately, they do this for fun and as a joke rather than its intended purpose. For example they use the invert colors shortcut (command + option + ctrl + 8) or the increase contrast (command + option + ctrl + period) to "mess up" the screens.
I know that I can disable the shortcuts via MCX and the com.apple.symbolichotkeys.plist but unfortunately this only works per user account when the students are logged in. I tried managing it as a computer preference, but since the /Library/Preferences does not contain this plist, it does not work. Does anyone know if there's a way to disable these hotkeys system-wide so they can't use the shortcuts on the login screen?