Plate IA: three cone types
Plate IB: colour space
Plate IC: the colour triangle
Plate IIA: successive colour contrast
Plate IIB: simultaneous colour contrast
Plate IIC: foveal tritanopia
Plate IID: red-green blind confusions
Plate IIE: an Isihara test
Plate IIIA: a contrast illusion
Plate IIIB: the Cornsweet illusion