We are taking our color direction directly from our subject. Here we see red violet and blue . We decide blue will be dominant. We choose a tetrad containing these two colors and let the harmony dictate the other two colors. Colors equidistant apart on the color wheel are, clockwise: Blue, red-violet, orange and yellow-green; two complementary combinations.
Make a light line drawing mapping the dimensions of the silhouette and value changes.
In addition to the four pure hues, choose their tints and shades. Use black sparingly. Look closely at the grid to see notations of all the pencils I’ve used next to each pure and mixed square.