Quick Theme provides a fast way to customize the colors of the Blender interface. It allows users to modify the color of the Interface, Viewport, and Outliner simultaneously using a single color slider. The Viewport and Outliner colors are linked to the main Interface color by default, with an option to unlink them for individual customization. An included Auto-Theme toggle can automatically apply a new theme each time Blender is restarted or a new project file is loaded.