Why are so many national flags three-coloured?

anyone seen this site?

http://ahpc-jp30.st-and.ac.uk/~josh/flags/intro.html

this guy gives a country’s flag a letter grade based on graphic design. Its got a lot of funny info.

Thanks for the info folks. Looks like it is a combination of inspiration and copycatting as well as following some design guidelines around simplicity.

That site is hilarious. I love the little icons he awards for aesthetic violations.

Saint Vincent and the Grenadines:

“Good effort for a country whose name sounds like a 50s rock’n’roll group”