For a cohesive and visually striking look, it is recommended to paint the metal shutters flanking the window in the same color as the maroon trim of the black quarter ball awning. By mirroring the maroon tone on both the trim and the shutters, you create a sense of harmony and unity in the design scheme. This not only ties the elements of the facade together but also allows the maroon color to pop and create a focal point against the black backdrop of the awning. Consistency in color choice helps to create a polished and coordinated aesthetic that enhances the overall appeal of the exterior. Therefore, opt for painting the metal shutters in maroon to complement the black quarter ball awning with maroon trim for a sophisticated and cohesive architectural look.