Of course I have to mention the other unexpected part of the Biostar Racing Z170GT7. I found it in a bubble ESD envelope. Pull out its contents, and you'll find a string of 5050 multi-color LEDs, bundled with the Biostar Racing Z170GT7 for free in America. There is also a sheet of paper with instructions.
5050 LEDs are now a common item both in home decor and the RC hobby world since they provide a simple way to add custom lighting to nearly anything you desire as long as you can provide a 12V power source. Since the majority of PC power these days is 12V-derived, it is only natural to see something like this included with a motherboard for you to add lighting to your case. 5050 LEDs can be cut to length in sections that are then soldered together with wires for you to space each three-LED section out at whatever distance you like. The included strip is encased in plastic to prevent shorting issues, which would make doing so a bit more difficult, but still possible. The backside has some strong 3M tape for you to attach it to the inside of your case.
The included string is about a foot long and has a plug you attach to the motherboard on one end, so it can be controlled via software in your OS. Since it offers 256 colors, you have a lot of options with the color you choose.
The plug on the motherboard is near the CPU fan headers; easy to locate. The color you choose is also matched by the onboard LEDs inside the CPU MOSFET coolers and at the board's left edge, right by the expansion slots.