I want to change the Unreal Editor's basic color.But i can't find to port,can anyone guide me?

I was research the UE4’s Editor. I know the Unreal Editor is written by Slate. And I can change the Unreal Editor’s Style through the Module of EditorStyle.
But i want to know if i don’t use the module of EditorStyle, how can i change the Editor’s apperance (such as the blank of the widget’s color). Can someone else
give me a guide. Think you very much.