It's a mixup of various rainbow effects. I pretty much use this setting as default. Designed for Corsair K95 Platinum, but was modified from an old Logitech profile I had.

Includes:

+Classical Rainbow Effect from left to right
+Breath effect with only letters and symbols
+Interactive keys (Rainbow Wave) only for letters and symbols
+Capslock and NumLock Filled Up color.
+The WASD and Directional keys are colored like the buttons on a Xbox Controller (Blue, Green, Yellow and Red)
+The mute button turns everything red* (Or when the system volume is 0)