Why St. Patrick’s Day Shifted From Blue to Green

The evolution of St. Patrick’s Day colors reflects Ireland’s history, nationalism, and cultural identity.

Historically, the color blue, known as 'St. Patrick’s blue,' was associated with the saint and early celebrations of his feast day.
Green became prominent in the late 18th century, symbolizing Irish nationalism during the United Irish rebellion against British rule in 1798.
The adoption of green was further solidified by its association with Catholicism and the Irish diaspora, especially in American St. Patrick’s Day celebrations.
In Ireland, St. Patrick’s Day remained a more solemn religious observance until the 20th century, with public celebrations and parades emerging later.
Although green dominates globally, St. Patrick’s blue continues to play a symbolic role, appearing in the Irish presidential flag since 1945.