How to set up SplitContainer in Windows Forms Visual Studio?

Question

C++ / C#

Help with SplitContainer in Windows Forms Visual Studio. I just can't figure out how to remove the dashed lines from the Split'er (I created 2 SplitConteiner and when another Split'er was selected, the dashed lines went to it, but disappeared from the first one), as well as how to color it (the Split'er itself, and not panel).