To turn as red as a beet is synonymous for an embarrassed blush. Like blushing, the red in beets is impermanent. The chemical that makes beets red is water soluble and if you were to dye cloth with red beets the color would immediately wash out. A popular red dye plant in the 1700s was Madder also known as Rubia tinctoria that is in the same plant family as coffee and quinine. The red dye for the British Red Coats were dyed with Madder roots as were the red stripes Betsy Ross’s first American flag.
Growing Home - Red Dyes
