The bright yellow tones in Van Gogh’s paintings have been fading and turning to dull browns. The changing color has been known about for some time, the problem is that no one knew why. However, now sophisticated x-ray techniques have been developed which have helped to identify the problem as a chemical change in one of the yellow pigments Van Gogh used. The “reduction” reaction alters the chromium in the paint changing the yellows to browns.
Researchers hope this new technology will advance the understanding of how paintings age and what can be done to preserve them for future generations.