How do you shut off the Touch Key Lights on a Samsung Galaxy Tab S2?

I just got my S2 and I absolutely love everything about it except the speaker sound quality (it kinda stinks). I upgraded from a Samsung Galaxy Tab 3 and what a different the 3GB of RAM (vs 1GB) and the AC wireless makes.

I am trying to shut off the "Touch Key Lights" (back arrow and...

How do you shut off the Touch Key Lights on a Samsung Galaxy Tab S2?