Limit access to brightness controls?

Hello,

I've gone through the trouble of calibrating the monitors in my office with my colorimeter. We publish photographs for print, so color accuracy is paramount. Unfortunately, not everyone in the office knows the importance of calibration and always turns the brightness to the max whenever they're on the computer. Needless to say, their stuff looks out of whack, sometimes even too dark, when viewed on another screen.

My current workaround is using Brightness to set a preset screen brightness for the screens, and changing it back whenever these guys mess with them. I'd like them to be completely unable to change brightness, perhaps without administrator privileges, so that we have consistent settings for everyone. If we disable the keyboard keys, they'll jump into System Preferences and change it from there. One idea I have is to have a launch agent run that brightness script every 1 second or so. Any ideas?