In which .plist is the underscan setting stored? I'm trying to write a script which changes the underscan value on my Mac mini, but I haven't found the .plist file containing the setting.

Does anyone know where the underscan setting is saved?
I found the settings file by using the terminal command opensnoop to monitor all files accessed by any programm and found that the file that stores the underscan setting is here:

/var/db/.com.apple.iokit.graphics