125 year consequence of being an early adopter
We don’t think about it much today, but portable paint was a big innovation in the 1800s. Artists previously had to mix their paint themselves using pigment and oil, which constrained most painting to their studios. But when the paint tube was invented in 1841, it meant that painters could venture outside, working with their premixed paints in the same natural light as their subjects. This is most apparent in the interest in many Impressionist’s work, such as Monet’s series of haystacks in different lighting conditions.
Vincent van Gogh was another early adopter of tubed paint. His brother was buying his paint, leaving us with records of what paint van Gogh was using. However, curators are now seeing that, like early iterations of many new technologies, there was a price to pay. In this case it’s proving to be the loss of red from his paintings.
Various paintings have been seemingly bleaching themselves, and after close analysis of some of the newly-formed white specs taken from the canvases, conservation scientists realized that the plumbonacrite, or red lead, is degrading with exposure to light. They suspect that, as one of the first industrially produced paints, the red lead carried some impurities which are now leading to the loss of color.
There are no plans to restore the color to the actual painting, despite the critical importance of color to these pieces of art. Instead, the Van Gogh Museum in Amsterdam is releasing an app to allow visitors to see a digitally enhanced version of the painting so that the original doesn’t need to be altered by modern hands.
Source: Why are van Gogh's paintings slowly turning white? by Shefali S. Kulkarni and Nina Porzucki, PRI's The World