In 2007, Shahee Ilyas decomposed the flags of the world’s nations into pie charts based on color. He then accumulated the color proportions into a single pie.
The work is visually stunning and, for me, thought-provoking. Please click on the graphic to go to his site. Hovering/clicking on the pies there provides the flags.
He used the World Factbook which is a good source for adventurers.