Hello, there is a small bug with the Corsair K100 RGB. Unfortunately, with a German keyboard layout, the “<” key (to the left of the “Y”) is also colored as soon as you color the G2 key.
That’s kind of normal as most plugins are created for ANSI keyboards.
If there’s no dropdown to select ISO in your keyboard’s settings in SignalRGB, you can follow this tutorial to correct it for your keyboard:
https://docs.signalrgb.com/plugins/converting-ansi-keyboard-plugins-to-international-layouts
Big thanks. Changed the layout and it works great. Only the instructions would have to be revised a bit 
Here is the finished layout for the German keyboard (keys also adapted or exchanged)