This paper is an historical overview of the influence of colour blindness in painting. The first part is a study of the ways of painting of daltonic subjects, which may be monochromatic, bicoloured, or polychromatic. The second part is an inquiry into colour blindness in art before Dalton, with necessarily hypothetical results, and after Dalton, when diagnoses were more easily made. The number of colour-blind artists in the history of art is probably larger than usually assumed, bur it is not possible to demonstrate daltonism simply by looking at an artist's pictures. The necessity of historical study is emphasized. (C) 2000 John Wiley & Sons; Inc. Col Res Appl, 26, S12-S16, 2001.