How blue is the visual art of our era? Interpreting the data of 94,526 paintings created between 1800 CE and 2000 CE, Martin Bellander, a PhD student at Karolinska Institutet in Sweden, discovered that blue has increased in art while orange has become less common.

Bellander was inspired by projects like data analyst Edmund Helmer’s 2013 look at the oranges and blues in film trailers, and relied on the BBC’s Your Paintings online database, Google Art Project, Wikiart, and museum sources to select 130,000 paintings and cut any without defined dates. Scraping information with R statistical software, a random selection of 100 pixels was taken from each piece and graphed over time, showing the increasing dominance of the moody blue tones. The visualization, shared with Hyperallergic by Bellander, is below:

After a friend’s Tweet got some internet attention, Bellander wrote a post about the process and included his code. He notes that there could be numerous reasons aside from artistic preference, such as the affordability and availability of blue pigment, the age of resins causing the perceived colors to change, or even the quality of the photographs.

“[T]he changes in color might be a result of a combination of factors,” he writes. “One of these could of course be trends in the use of color. If we assume a smooth linear deterioration of certain colors in oil paintings, it would be possible to subtract that change and study the short term fluctuation in color use. For example the marked increase of blue at the time of the First World War, might actually reflect a true trend in color use.” He adds that he’s interested in finding more details on such data as photographic quality and is welcoming suggestions in the comments on how to improve the visualization.

Read more about the data visualization of painting colors from 1800-2000 on Martin Bellander’s blog.

h/t Washington Post