Olive green is a darker hue of the primary color green, but its rich earthy tone is only achieved by mixing the correct combination of several different colors. The exact proportions you will need of each color vary based on medium, but the basic ingredients are always the same. This natural pigment is easily created from mixing variations of primary colors.
A basic olive green is created by mixing cobalt blue, crimson, and burnt umber. The hue of the color can be changed by varying the proportions of the mixture, and the value can be changed by adding black or white into the mix.