My eighth graders work with Sax tempera paints. We discuss the three
characteristics of color: hue, value and intensity. They mix and paint
color value studies: add white to make lighter and black to make darker.
They mix and paint intensity studies: add the complement to make the color
duller until they reach gray (they sometimes need to add white to the
mixture to see the gray which can be pretty dark.) Then they have to match
colors. I take those color strips from paint stores and cut them up into
squares, and students have to match 3. We use this "formula": determine
the hue(s), the value (either light or dark), and the intensity (either
bright or dull). Once students have made the determinations for the chosen
color square, they know which paint colors to squeeze out and mix. Then
it's trial and error until they find the correct proportions. I do
demonstrations. I keep a magenta handy for some colors that require a cool
red and the regular blue and ultra blue for the warm and cool blues. Final
projects differ depending on the class.
Another "practice your color mixing" activity is to have students trace
one hand and then using only red, blue, yellow and white, have them mix
their hand color. Best to start with white, then add some red and yellow,
then in minute amounts add blue bit by bit until you find the correct
brown. You can add a multicultural link to this by talking about how
everyone's skin color is made up with the same 3 hues, just in different
proportions. This activity was featured in Tolerance magazine a while
back, but I've been doing it for many years before that.