Orange and the violet used in this sketch are two thirds of a triad. For this one I threw in some single-color accents of yellow, yellow-green, and blue, just to see how they went together. Yellow-green and blue are half of a tetrad with orange (and red-violet, missing here.) I subscribe to the idea that color combinations are completely analagous to chords in music, and that you can get a lot more interesting art when you use more complicated harmonies. Sometimes what you leave out is as important to the feeling as what you put in. But whether or not any combination actually works in a painting depends on placement in relation to the other colors, relative size, saturation, and how it supports both the subject and the idea of the painting. Only seeing and feeling it can tell you if you've hit the mark—you have to play to learn.
I think if I moved these colors around in the painting I could get several different moods, as I could if I used different values. It's a mix that carries a lot of energy and seems to beg a lot of "why?" questions, which really stimulates my imagination. Orange suggests earth and sex; violet points to spirit and the higher mind. Orange feels grounded and practical; violet leans toward infinite space and unbounded imagination.
One thing for sure—I'm never going to get tired of color.