8 x 8 inches, oil on canvas
Here's a painting I did using only the primary colors (Cadmium red, Cadmium yellow, and Ultramarine blue), plus white. A great way to capture truly brilliant bright reds is to lighten them by adding yellow instead of white. Titanium white has a blue cast, which ever-so-slightly cools and dulls orangey Cad red. A dash of yellow lightens it, keeps it saturated, and gives it a warm kick that helps it advance towards the eye.
Here are the three stages of my painting. First, I tone the canvas with a dull orange I mix from all three colors, laying in my drawing and pulling out some highlights. Second, I firm up my drawing with a darker shade, indicating my darkest darks and noting the overall value scheme. And third: add color!
Step two-and-a-half - not shown here - is paint mixing. With a palette knife. A lot of it. :)