Did you see "Braveheart" it starred Mel Gibson. When they went into battle they painted thier faces blue. There may be some connection as it was about early Scotland/Ireland.
The majority of the Scots arrived in and around North Carolina in the mid-1700's after a battle supported by 'Bonnie-Prince-Charles' which they lost. Many fled to America where they made their living by boiling down pine-rosin for pitch used on the ships of the king of England. The term 'tar-heels' comes directly from these people who were always mucking around with pitch, tar and etc.
Never expect a movie to teach you history. The "blue" in braveheart was for Hollywood effect.
I saw a show with a British historian, and she said maybe very primitive tribes perhaps did this at one time, but the practice was way over by the time of Braveheart.
They also had a famous bridge battle in Braveheart without the bridge. Cost too much money. LOL.