The Rainbow Swash is the official name for an untitled work by the late Sister Corita Kent, a Roman Catholic nun and artist, in Boston's Dorchester neighborhood. (We always just called it the "Sister Corita splashes''). The design, painted on a 140-foot-tall LNG storage tank, on Boston Harbor, is called the world's largest copyrighted work. It's highly (too?) visible by the hundreds of thousands of tortured commuters driving on the stretch of Interstate 93 called the Southeast Expressway, aka Distressway or World's Longest Parking Lot.
The design first went up in 1971 and was transferred to its present location in 1992, after the original LNG tank on which it was painted was torn down. The pattern seems a relic of schlock and pop art of the '60s and '70s. It was controversial for a long time because some said they saw the profile of Vietnamese Communist dictator Ho Chi Minh in it. Remember that the U.S. was in the Vietnam War until May 1975. Sister Corita was said to be a bit of a lefty and was a pacifist.