I suggest you divide your project into two areas: window docking and management; and, themes.
Both these libraries offer you some powerful tools for window management:
1. On CodeProject there is Chris Richner's May, 2013, article: Magic Library Docking Manager Designer: [
^].
2. A powerful open-source library for multi-window docking, and dynamic re-sizing, in Win Forms C# is Weifenluo's DockPanel Suite: [
^]. DockPanel has (last time I looked) some support for use in Mono (I don't use Mono).
If your goal here is not just to find a "solution," but, to develop yourself as a programmer in C# Windows Forms, learning how to simulate docking of Windows is a very good experiment.
Happy New Year (western-style)