Van Gogh’s changing colours

Banks of the Seine (top) and View of Arles with IrisesUltraviolet rays are behind some of the bright yellows in Vincent van Gogh’s paintings turned brown.

The finding is a first step to understanding how to stop some of the Dutch master’s paintings from fading.

Two chemists, Koen Janssens from Antwerp University and Letizia Monico of Peruga University in Italy, studied three paintings at Amsterdam’s Van Gogh Museum—Banks of the Seine, View of Arles with Irises, and an unnamed painting. In a letter to his brother, the artist described the Irises as having “startling citron background”. It’s now a misty pinkish-taupe.

The chemists exposed three Van Gogh-vintage paint tube samples to UV light simulating a century of exposure; one sample showed major color shift. Art historian William Poundstone said, “Van Gogh bought the cheapest art supplies and lived where fate took him. It’s not hard to believe some of his paintings had stable yellows and others didn’t.”