Watercolor Color Mixing Chart: Sap Green and Rose Madder. This watercolor chart was painted by Frances in preparation for painting her Kona Hibiscus http://painting.about.com/od/colourtheory/ig/color-mixing-charts/Watercolor-Color-Mixing-Chart.htm It shows beautifully what a range of colors can be mixed from just two.
Also on these boards
Art Journey Techniques: New Basic Flesh-Tone Palette
Covetable collectible: a vintage Jung Koch Quentell school pull-down chart.