Use the compass to draw a light circle in pencil on the card stock. Make three light pencil marks evenly spaced around the circle to indicate where the primary colors will go.
Paint a small patch of blue at one of the marks, red at another, and yellow at the third, cleaning your brush thoroughly in lukewarm water before switching colors.
Make light pencil marks along the circle halfway between the color patches to mark where the secondary colors will go.
Mix blue and yellow in equal parts and use the resulting mixture to paint a green patch between yellow and blue. Clean your brush, then repeat the procedure: mix red and yellow to make orange, then paint an orange patch between red and yellow; mix blue and red and then paint a purple patch between blue and red. Make sure to clean your brush between every color change.
Complete the color wheel by painting patches of the tertiary colors. For each blank spot between a primary and secondary color, create a mixture using three parts of the closer primary color and one part of the farther one. For example, to color the spot between blue and green, mix three parts blue with one part yellow. Be sure to clean your brush between every color change.