Dark Walnut is an iron oxide base pigment. Viewed in the bottle, as well as when firs tattooed into the skin, this color appears olive green. Dark Walnut will heal into a medium brown color. The olive green is necessary to compensate for the red undertones prevalent in some brown pigments. This modification reduces the risk of your client's eyebrows turning pink. To test for a color tone and the depth of color, smear a dab on the client's skin. Dark Walnut can be mixed with any of the eyebrow colors and with some of the camouflaging pigments. Some suggestions on color variations would be mixing in Taupe, Sterling Grey, Black Onyx, Jade or Moroccan, or combination of two of them or more.