Can anyone make an Apple Script for me?

There is evidently no direct way to do this, but there is an indirect way:

1. Download an app called SleepDisplay: Download SleepDisplay for Mac - Put your display to sleep instantly. MacUpdate.com
2. put SleepDisplay in your Applications folder
3. open Automator.
   1. Select service for type of document
   2. at the top, for service receives, select no input, and after in, any application
   3. in the column on the left, select Utilities
   4. in the next column, drag Launch Application over to the right, and select SleepDisplay for the app
   5. close the window with the red circle in the left upper corner, and give the service a name, like Dark.
4. go to system preferences > keyboard > shortcuts
5. select services in the box on the left, and scroll down in the box on the right until you find the service you just created. select that service.
6. when you select it, a white oval should appear that says "add shortcut". Type in the shortcut you want to use. I couldn't get ⌘F1 to work, but control-option-⌘-D did work.

   It must be a unique shortcut, not already in use.

Arthur,

That download is not tested with anything above Snow Leopard. Are you sure it even works with Mavericks?

Yep. Just tested it.

You will find something you can use here. The command can be used in an Automator action and tied to a keyboard shortcut similar to what Arthur has already posted.