Using 3 nested SplitContainers in my Windows Forms Application. When encountered the same problem that other have with the splitter bar being the same color as the surrounding panels. The common solution seems to be to change the BackColor but when nesting this results in an unsightly border around the nested panels:
I've also people suggesting the use of the Fixed3D BorderStyle but this has the same problem:
In the last moments of writing this question I had an epiphany. The dotted lines inside the SplitContainer are just guidelines and not a fixed margin. The location of the nested SplitContainer is 3, 3.
By manually setting the location to 0, 0 (the designer snaps to 3, 3) the grey on the left disappeared. I also had to enlarge it by 3 pixels to prevent a new border on the right.
Doing this to each nested SplitContainer solved my problem: Fixed form http://fr33dan.com/Fixed.png