Once you have determined the values in your reference photos you’ve got to figure out how all of those paints you’ve got translate into value numbers.
I take each of my inks and put them on a little piece of photo paper and punch holes in them so I can arrange them by hue (color). I have a separate ring with all of my colors by value.
For this example I laid out all of my green color chips:
Here are the green color chips arranged by gray-scale value from darkest to lightest.
Here’s Chui, a cheeta, that works because the values are correct. Let me know if you ever see one with these colors.
(click to enlarge)