In the early days of weaving, only natural dyes were available to colour wool. These were often derived from boiled vegetables, plant roots and insects. Reds came from madder roots or cochineal beetles; blues from the indigo plant; yellows from Persian berries and turmeric; browns from walnut husks, oak bark and pomegranate skin; orange from henna leaves, and green from a combination of weld and indigo.
Using natural dye is both environmentally friendly and gives the wool a more beautiful look, but more importantly it does not affect the quality of the wool. Natural dyes can produce a wide variety of tones, and in time will mellow with age, like a good wine.