When did Kermit the Frog say its not easy being green?

Kermit the Frog first sang the iconic line "It's not easy being green" in the 1970 song "Bein' Green," which was featured on the television special "Sesame Street" and later popularized in "The Muppet Movie" in 1979. The song reflects Kermit's feelings of self-acceptance and the challenges of being different. It has since become a defining moment for the character and a beloved part of Muppet lore.