Part of me wants to believe the song was originally Lavenham's Blue because of this bit of history.

"Lavenham prospered from the wool trade in the 15th and 16th century, with the town's blue broadcloth being an export of note. By the late 15th century, the town was amongst the richest in the British Isles, paying more in taxation than considerably larger towns such as York and Lincoln.[4]"

Lavenham - wikipedia

The wool colour was referred to as "Lavenham blue" by the literature and guides when we visited Lavenham Guildhall. Reaching? Of course. But I like to imagine a young Henry VIII wooing his beloved with this song.