From the manufacturer:

The Complexion Palette is the fifth addition to the Skin Illustrator line.  The palette was created to give artists a wider range of red tones and adjusting colors which allow the fine tuning of an appliance makeup or to help blend the appliance with the natural skin tones.  The Complexion Palette is an excellent way to fine tune your makeups - a definite must for your makeup case! These colors are ideal for beauty, character and special effects make-up.