Annie Sloan Chalk Paint Color Wheel. Color + Old White = Tints. Different amounts of Old White (or Pure White) combined with a color will yield a progression. This is helpful in extending your range of colors no matter what type of paint you are using.
Each color was hand painted and scanned into my computer for color accuracy. However, colors displayed on computer screens are likely to be different from one computer, ipad, iphone to the next. The only way to ensure color accuracy is to view a hand painted sample in person, in different lighting situations. Something I have learned the hard way, with a lot of practice and mistakes.