St Patrick's Day coloring pages depict green ribbons and shamrocks were worn in celebration of St Patrick's Day. It is said that the shamrock, a three-leaved plant, explains the Holy Trinity to the pre-Christian Irish, and the wearing and display of shamrocks and shamrock-inspired designs have become a ubiquitous feature of the day. The phrase "the wearing of the green", meaning to wear a shamrock on one's clothing, derives from the song of the same name.