Purchase all the basic process colors and a color-mixing book from the ink supplier. The book will specify the right amount of ink needed to make a specific color shown. For instance, it may tell you to make deep purple, mix 75 percent Reflex Blue and 25 percent Violet.
Convert the percentages into ratios like a 3-to-1 ratio.
Place the ink in a small glass container and place on a scale to measure the correct ratio. Mix the inks together with an ink or watercolor paint brush to make the needed color.
Make a basic ink color wheel by painting your screen printing ink primary colors of cyan, magenta, and yellow in an equilateral triangle form on a piece of white paper or cardboard. Paint a cyan circle at the bottom right hand side, a magenta circle on the bottom left point, and a yellow circle at the top point. Connect the painted spots with a pencil line made using a ruler. This will make the equilateral triangle. These are the screen printing subtractive method primary colors.
Draw a circle through each of the painted colors and around the color wheel triangle using a pencil and compass.
Mix equal amounts of magenta and yellow on a piece of glass and paint a red circle between the yellow and magenta circle. Mix equal amounts of yellow and cyan to make green and paint a circle on your drawn circle between the yellow and cyan circles. Mix equal amounts of cyan and magenta to make blue. Paint this circle on the drawn pencil circle between the cyan and magenta colors. These are known as the additive primary colors and other colors can be achieved by mixing these primary colors.
Mix secondary colors and place a painted circle between each of the painted circles to remind you which colors make the secondary color. Mix red and yellow to make orange, yellow and blue to make green, blue and red to make violet.
Add more of one color and less of another to create the tertiary colors. For instance, add 2 parts yellow and 1 part red to make a pumpkin color. Mixing different amounts of primary colors will give you the tertiary colors. You can only mix the primary colors that sit next to each other on your color wheel. Mixing primary colors that sit opposite each other will give you a brownish, muddy color. Use your color wheel as a mixing guide for your inks.
Add white and black ink to make different tones of these primary, secondary and tertiary colors.