Quote Originally Posted by Tim Walker
As I recall, Saltire refers to a pattern used for certain flags.
Yes, as Todd said, in heraldry and vexillology, it's an X-shaped cross, also known as St. Andrew's cross. The national flag of Scotland, a blue ground with a white St. Andrew's cross from corner to corner, is known as the Saltire because it has the saltire motif on it. St. Andrew is the patron saint of Scotland.

The Saltire kilt is meant to evoke the Scottish flag, and when I said it's the proper shade of blue for the Saltire, I was referring to that flag.