Premise: "The Orange and the Green" or "The Biggest Mix-Up" is a humorous Irish folk song about a man whose father was a Protestant ("Orange") and whose mother was a Catholic ("Green"). It describes the man's trials as the product of religious intermarriage and how "mixed up" he became as a result of such an upbringing.
Hypothesis: The song is about a father who was a Protestant (Yellow) and whose mother was a Catholic (Green).