The story of Izamal is that the Pope visited around 1995 and to honor him everyone painted their houses and businesses yellow. I am uncertain who paid for all the paint but the color has been maintained. Izamal is located east of Merida on the Yucatan Peninsula. There are three Mayan ruins located in the town which each have been partially dismantled by the colonists to build Christian churches and Haciendas.
And a very active market place also located on the town square.
Also a lovely museum of contemporary crafts.