Vincent van Gogh painted his famous 'Sunflowers' series in 1888 to decorate the bedroom of his friend Paul Gauguin in the 'Yellow House' in Arles. For Van Gogh, the sunflower was a symbol of gratitude and the sun-drenched landscape of the South of France. He used a newly invented pigment called 'Chrome Yellow,' which allowed him to achieve a brilliance never before seen in painting. However, Chrome Yellow is chemically unstable; over time, it reacts with light and turns a brownish-green, meaning the paintings we see today are much darker than what Vincent originally intended. Despite this, the series remains a masterclass in the use of 'impasto'—the technique of applying paint so thickly that it stands out from the canvas, creating a three-dimensional texture that reflects light in different ways.