Cheap or DIY Keyboard Overlays?

I am in charge to furnish a class with keyboards that have colored keys for special functions. It's for kids in their free time to learn video cutting and editing (mainly on Final Cut Pro).

Now, these Logic Keyboards or Overlays already exist, but are fairly expensive, and as you can imagine, there is not much money in such free time projects.

Does anyone know of cheaper/simpler solutions ?

We are quite a handful of helpers with different handcraft skills, so we are going to try this on our own if we do not find a buyable solution. The results will of course be on display here, if not considered off-topic.

No, the Optimus Maximus is not a solution :)

Solution 1:

This is the cheapest thing I could find:

http://www.4keyboard.com/apple-final-cut-keyboard-stickers-p-176.html

Solution 2:

It looks like this guy may have put together something that'll do in a pinch. It looks like people have added schemes for non-game-related overlays, so I'd imagine you'd be able to use it for your purpose.

(I haven't used them, but it looks promising.)

Solution 3:

In the good old days, PC gaming magazines would print a double A4 card printed sheet designed to fold out & fit over standard keyboards for popular games. Not so much an overlay as a keyboard attached cheat sheet. Kind of like the old TI-99 overlays.

Not an ideal solution but both cheap and simple!