They mix the secondary colors of orange, green and violet. They also create the six intermediate colors. Those are yellow-orange, yellow-green, red-violet, red-orange, blue-green, and blue-violet.
Here are the formulas and how I teach students to mix those colors.
R + Y = O
R + B = V
Y + B = G
To mix the intermediate colors you
Add a little red to the yellow to make yellow-orange.
Add a little yellow to the red to make red-orange.
Add a little blue to the red to make blue-violet
Add a little red to the blue to make red-violet.
Add a little blue to the yellow to make yellow-green.
Add a little yellow to the blue to make blue-green.
Once they have a handle on all of that, we move on to mixing tints, shades and tones. We use the neutral colors of black, white and gray to create these. One rule I have when mixing these is ALWAYS add the darker color to the lighter color.
A tint lightens a color, so add the color to the white a little at a time to create various tints.
A shade darkens a color, so add the black to the color a little at a time to create various shades.
A tone dulls a color, so add the color to the gray when mixing various tones.
Now... on to the lesson. Every year I have had students create wheels and repeat the designs in them. They always turn out great, but I put a different twist on the wheel this year. Here's what I did.
1. Draw a large organic leaf form from top to bottom on a 12 x 18 white paper.
2. Divide the leaf in half vertically.
3. Create six sections on each side of the leaf. (Like the veins on a leaf) You now have 12 sections.
4. In each of the sections create 7 areas to paint. Students will paint two tints, two shades, two tones and the main color in each section. I had them try to create the same design across from each other to get a symmetrical look....even though it is not truly symmetrical. In the past the transfer process of their design always took a lot of time. Now, they can simply freehand their design.
Here is an example of what it should look like before they start painting. I also have them label each section with the colors so they don't accidentally paint colors in the wrong spots. This also gives me a quick overview of who knows the color wheel order and who still needs help.
This lesson takes us 5-6 class sessions, but it is well worth it because they are learning to create 84 (12 sections x 7 different colors) colors and they have an understanding of how to mix these colors. Here are some of the finished color wheels. Once painted, they outlined the different colors in black marker and cut them out and glued them onto a neutral colored background. This lesson is done before I commission them to paint a landscape. Look for those in the near future.