“b” or “β”
n Yellowness-blueness coordinate in color spaces, Δb, the difference in “b”, between a specimen and a standard reference color, normally used with “a” or “α” as part of the chromaticity difference (McDonald R (1997) Colour physics for industry, 2nd edn. Society of Dyers and Colourists, West Yorkshire). If “b” is plus, there is more yellowness than blueness; if “b” is minus, there is more blueness than yellowness. The exception is Adams Chromatic Value. See also Uniform Chromaticity Scale Diagram and Color Difference Equations.