Here's a recently completed quartet of paintings that are unified both in composition and color theory. The repeating vertical elements create strong unity from a design standpoint. And the common theme of cool colors over warm colors tie the four paintings together from a color standpoint. Even with those similarities the four paintings make a highly tensional visual statement thanks to the variety of warm colors in the background. Red, orange, yellow, magenta and pink.
Take a look at my Instagram page to see the progression of this piece from start to finish.