I'm new to Inkscape. I just installed it on my Ubuntu laptop and I noticed this screenshot on the inkscape website with a darker skin than the stock one. I really like to use dark skin since it won't disturb my eyes from the canvas (I use it that way when doing video editing and 3d work). The screenshot I'm talking about:

I tried doing it on my own, but I could even find any preferences or anything.
Thanks in advance,
Arnar.