Look at that dual-channel RAM set-up of yours. Are there two extra DIMM slots waiting to be filled? How sad. With RAM prices as they are, those slots might not be filled anytime soon—unless you go with Corsair's alternative: the Vengeance RGB Pro Light Enhancement Kit, a $40 package with two mock RAM sticks that use 10 addressable RGB LEDs each.
Yes, it's purely for aesthetic RGB purposes. Talk about solving first-world problems. If for some reason you are bothered by not having a full motherboard, this will fill those spaces until memory prices drop.
Corsair isn't the first company to do this: Back in June Gigabyte revealed its own Aorus RGB LED kit with two sticks of actual RAM and another two without any actual memory but plenty of lighting for your computer.
This clearly marks a trend: dummy RAM sticks for decorative purposes are here. It won't provide any performance benefits, but it sure is pretty.
Or you could stick with a few empty RAM slots. Worse things have happened.