Originally it was blue.
Green
Green is most associated with St. Patrick's Day.
Saint Patrick's ministry was in Ireland, and Ireland is known for its green landscape. Green is the color of Ireland (often called "The Emerald Isle"), the color of shamrocks, the official "Irish" color, as it were.
green (by the way it's favorite)
A shamrock.
Green is the primary color of St. Patrick's day.
White and gold are also prominent.
Green :)
I guessing you mean why people wear green. Well that can be a number of reasons but usually in today's society green symbolizes recycling and earth, basically being an environmentalist. Although green can also be associated with st patricks day and the Irish. There are many reasons someone might wear green it is a very good happy color
It is Ireland that is associated with green such as 'St. Patrick's Day' with Shamrocks. Scotland is not associated with green with the exception of some tartans in the kilts.
It was originally blue, but over the years people started wearing green instead.
Green.