Why is the Scottish flag blue and white?

The origins of the Scottish flag lie in a tale from 832 A.D. when King Angus II dreamed before a battle that Saint Andrew will protect them in the following day. The next day the white clouds formed a Saltire cross with the clear blue skies as a background.

The Saltire is defined by diagonal bars of equal length in the shape of a tilted cross and is also known as Saint Andrew's cross. The first illustration of the Saltire flag was in the 16th century. Some changes occurred between that period and 2003, when the Scottish Parliament standardized the shade of blue used as the background. The Saltire Memorial was created in the memory of King Angus II's victorious battle at Athelstaneford.