Green is associated with St. Patrick, not red.
Snakes are associated with St. Patrick. Legend says he drove all snakes from that country. However, there is no fossil evidence that snakes ever lived in Ireland.
While the story could be an allegory for Patrick bringing Christianity to Ireland to displace the Duidic religion, it could also be just a fanciful story to explain why there are no snakes in Ireland.
A leprechaun is generally associated with Ireland, not just St. Patrick's Day.
Green is most associated with St. Patrick's Day.
I'm betting it Saint Patrick.
Leprechauns are traditionally associated with St. Patrick's Day.
Green.
Green, which is the colour associated with Ireland. St. Patrick is Ireland's patron saint and St. Patrick's Day is Ireland's national holiday.
Legend says that St. Patrick died on March 17 so that is considered as his feast day - when he entered Heaven.
Green
The keys of St. Patrick symbolize the power of spiritual authority and the responsibility to guide and protect the faith. According to legend, St. Patrick was given the keys to heaven as a sign of his role as a spiritual leader and protector of the Christian faith in Ireland. The keys are often depicted in art and imagery associated with St. Patrick as a symbol of his significance in the Christian tradition.