Automator Scripts for "Universal Access" contrast screen?

[Matt OS X]

There's a client who have usher syndrome and prefers to use Universal access's "White on Black" display (contrast). Can anyone help me with Automator or Apple Script for enabling 'white on black" contrast display every time when he logs in?

I tried Automator and Applescript and I dont understand how it works. I'm a newbie here obviously- Please help me out asap. Thanks

[#1 Rhapsody]

Once you select "White on Black" it should stay that way as long as it is enabled. If it doesn't stay enabled, click the lock in the corner to lock it.

[ElDiabloConCaca]

If it doesn't stay enabled, click the lock in the corner to lock it.
The lock icons in the System Preferences have nothing to do with whether an option stays enabled or not.

The locks are for authorization purposes, not "locking" a preference so that it doesn't change.