Alder Buckthorn or Rhamnus Frangola was a popular dye in Europe, and it can be used without a mordant, or any assists, to make the color of the reddish brown. The bark was used here although the berry can be used too. This dye came to me via a friend that bought it for medicinal purposes. Gallnuts (tannin) are the yellow that I used to make green with a few grains of iron. The bowl of light is drawn with Brazilwood. The dark brown was a complete surprise here, and I was unhappy with it at first. Oregano has iron: Iron and a plant with tannin creates a deep brown!