Values and the Practical Colour Wheel

The Second purpose of the colour wheel arranged this way is to provide a value vs. colour guide.  Looking at the PCW (Practical Colour Wheel) you will find a grey scale on the left hand side.  This value scale ranges from black on the bottom to white at the top.  The pigments on the wheel correspond roughly to this value scale (If you wish more detail on this, write to me).  For example, Cadmium Lemon Yellow is about a 9 on the value scale.  Its near complement Dioxy Violet is about a 1.  Most of the pigments are in middle values.

Practical Colour Wheel vs Value

This might seem trivial.  However, when teaching I find that many people struggle with value once colour is introduced.  The result is a painting with middle values.  Such a painting is read as dark, lifeless, or perhaps reflective of a rainy day when indeed it is a bright sunny day.  I see countless paintings in juried shows exhibiting the same look.

A reference to the wheel would tell a painter that a sky painted with a mixture primarily of Ultramarine Blue (value ~2) would have to be lightened significantly to bring it to a 9 if that is what you see.

In addition, there are value checkers available commercially.

This configuration can also lead you to mixtures for a beautiful dark instead of using a dull earth tone such as Burnt Umber.  For example, the complements of Viridian plus Alizarin with the addition of Ultramarine form a juicy rich dark especially when not over-mixed.