colour-proximity
Get a value of the proximity of two hex colours.
This package also exports rgb2lab([r,g,b]), a function that converts RGB to Lab* at Observer=2° and Illuminant=D65
Example
colour-proximity.proximity("#ffffff","#fffffe") // 0.5074219151751335
colour-proximity.proximity("#ffffff","#000000") // 100.000000625
Install
npm install colour-proximity