You can use the GETTING TO TERTIARY TEMPLATE as a color mixing exercise.
Use a copier to enlarge the worksheet to a size that is comfortable for you.

Use the three Primary Colors to develop the three Secondary Colors, and then use the Primary and Secondary colors to make the six Tertiary Colors.

Use the 3 primary colors (yellow, red, blue) to paint the acorn in the center.

See the color wheel to mix the secondary colors, then use the primary and secondary colors to paint the inner circle of leaves.

See the color wheel to mix the tertiary colors, then use the primary, secondary and tertiary colors to paint the outer leaves.