Triad with split complements is a wonderfully flexible color scheme, especially when you expand the definition a bit.

Trumpet Parts No. 51, ink and watercolor sketch

Playing The Color Scheme Game I threw an eleven (Triad with Split Complements) and an eight (Dominant Color is red/violet, split complements are green and yellow).  For a more dynamic layering of color shapes I extended the dominant color of red/violet to include a cooler violet.  For me, triad schemes provide more opportunities to create strong color interactions and visual movement than analogous color schemes.  I prefer analogous schemes for meditative, soothing imagery.

Ink and Watercolor Sketch: drawn first with fountain pen filled with black ink followed by watercolor.