The article delves into the tradition of wearing green on St. Patrick's Day, exploring its roots in Irish history and culture. It highlights the significance of green in Ireland's landscape, folklore, and national identity, and how St. Patrick used the shamrock to explain Christian beliefs. The transformation from blue to green as the color of St. Patrick is examined, alongside the nuances of its adoption across Catholic and Protestant communities. The global celebration of St. Patrick's Day, with landmarks worldwide illuminated in green, showcases the universal acceptance and joy of this tradition, transcending its origins to unite people globally in celebration of Irish heritage.