Blackwatch
A tartan of green on midnight blue
Named for the Black Watch - Her Majesty's 42nd Royal Highland Regiment
One of the oldest regiments in the British Army the Black Watch were originally formed to keep the somewhat lively Highlanders in check, the sort of thing Plod does now
The name comes from Black (meaning bad) and Watch (meaning to spy on)
An example of the Black Watch regiment's history;
Two platoons were en route for a Little Unpleasantness in South Africa when their ship struck a rock and broke in two. The ship's crew told the men their only hope lay in swimming for the lifeboats. However their officers pointed out that if they did so they would endanger the women and children already in the lifeboats. The men of the Black Watch stood firm in their ranks.
A Gentleman does not forget this when wearing Black Watch