Fugitive pigments

Fugitive pigments, in painting, are non-permanent pigments (pigments that lighten in what is understood to be a relatively short time when exposed to light).

While most paintings are supposed to be done with permanent pigments, painters have made work wholly or partially with fugitive pigments for a number of reasons: ignorance as to the permanence of the pigments, prioritising the appearance of the colours one can get with fugitive pigments over permanence, or the desire to have a painting change in appearance over time.