Hey Ben , check this site out. I have used this color chart , it works.
Site: (one-ring.co.uk) enter the site called (one ring)
Once ypu enter , on the left side , look for (Tomes of Wisdom) , click on the (Painting Guides) next page will read ,
Sub-categories , click on (Foundations of Miniature painting) , after it loads , drag the screen to (Mix paints from primary colors) click on it , the paint chart will load , it will say like ( 4 drops black + 5 drops blue = Midnight Blue)
Hope this is what ur looking for ...... Mike