The mixing is the first. But a detailed color wheel would be very helpful in your process. Ends by the means.
Color indexing is a science in itself. One for paints, one for monitors, one for printing, inkjet, laser, 8+ color lithographic press.
Press Operations Markup departments have very sophisticated tools. They must intermittently index their monitors to the pallets of the colors used by the print department (I've worked in this world).
Search for a color wheel, more details are better. You will have something you can use as a reference.