Use the ruler to divide the paper/cardboard/poster board circle into six equal sections. The circle will look like a pie when completed.
Paint a section of the color wheel red. This will be section one.
Paint section three of the color wheel yellow and section five blue. These three colors are called primary colors. This means that you cannot create these colors by mixing other colors together.
Mix equal parts of yellow and red paint to make orange. Paint section two orange.
Mix equal parts of yellow and blue to create green. Paint section four green.
Mix equal parts of blue and red paint to make purple. Paint section six purple. These colors are called secondary colors because they can be made by mixing primary colors.
When paint is dry, thread the needle with string and poke a hole in the middle of the color wheel (where all of the points meet) and pull the needle through so string is on both sides of the paper.
Spin the color wheel by twirling both sides of the string. As long as the colors were mixed correctly and each section of the wheel is equal to the others, the color wheel should appear white when spun.