has dye extraction from sappan wood as food colourant been done before?

Answer 1

yes, there are lots of sources, one that I found interesting was this one:
"here are European records of true red dyes during the Middle Ages, primarily from the heartwood of an Asian tree called sappanwood (Caesalpinia sappan). Sappanwood is native to India, Malaya and Sri Lanka, and is cultivated throughout the Asian tropics. The wood was imported into Europe since medieval times, but only in limited quantities. The dye was a beautiful red, the color of burning coals (in Old French and English "braise") and was called bresil or brasil by the early Portuguese traders. In 1500, Portuguese ships discovered and claimed the Atlantic side of South America that straddled the equator and the tropic of Capricorn. This massive land was called "Terra de Brasil" and later Brazil, because of the dyewood trees (Caesalpinia echinata) that grew there in abundance. Like the closely related sappanwood, the valuable dye from brazilwood (called brazilin) became a popular coloring agent for cotton, woolen cloth and red ink. As with precious cargoes of gold and jewels, Portuguese ships loaded with brazilwood were favorite targets of marauding buccaneers on the high seas."