Primary Colours
Colours that “cannot be obtained by mixing other hues, but one can produce all the other hues by mixing the primaries.” (red, blue, and yellow)
Secondary Colours
Colours “made by mixing their adjacent primaries; for example, yellow mixed with blue makes green.”
Tertiary Colours
“A mixture of primary and secondary hues: yellow-green is a mixture of the primary yellow and the secondary green.”

To get a better feel for this, go and look at some on-line art and examine the works with primary, secondary and tertiary colours in mind.
For the classroom, primary, secondary and tertiary colours can be the focus of any art lesson. Some ideas:
- Rubbings with crayons; the layers of crayon will show the mixing of the colours.
- Mixing coloured play-dough
- Make color paddles out of cellophane with red, blue and yellow in tagboard frames.
- ‘Mix’ colors by holding color paddles together.
- Mix colored water together and see what colors they make.
- Add white and black to different colors and see what happens.
Books
Colour wheel image and quotes from Drawing: a Contemporary Approach Third Edition, Claudia Betti and Teel Sale, Pub. Harcourt Brace Jovanovich, 1992.
Internet Resources
My Many Colored Days by Dr. Seuss