In the English Civil War, since they were people of the same culture and same (original) government fighting in the same armor and the same clothing style, and didn't have a whole lot of time, on account of it being a civil war, to prepare nice forms of distinction, simple colored sashes were commonly worn by officers and cavalry - either around the chest or around the arm - to distinguish friend from foe.
Later in the war, the New Model Army would use proper uniform coloring.