A Software Engineer by the name of Vijay Pandurangan created an interactive infographic showing how colors have evolved in movie poster from 1914 to today.
Click on the large color graph on his site, if you then click on any of the years, it will take you to a pie chart showing the breakdown of movie titles/colors. The pie chart has a slider at the top that you can then drag to go from 1914 to 2012.
How he did it:
"I downloaded ~ 35k thumbnailed-size images...from a site that has a lot of movie posters online. I then grouped the movie posters by the year in which the movie they promoted was released. For each year, I counted the total number of pixels for each colour in the year. After normalizing and converting to HSL coordinates, I generated the visualizations."
Why he did it:
Who the f*ck knows.