colorparsley
colorParsley() • a lightweight yet versatile color parsing function with no dependencies. Takes various color strings, numbers, or objects, and turns them into simple arrays. Bonus utilities colorToHex() and colorToRGB() included
chromatism
A simple set of utility functions for colours.
apca-w3
APCA: the Accessible Perceptual Contrast Algorithm, a modern contrast method that improves readability contrast on self-illuminated displays. Developed for the W3C's WCAG 3 and other standards.
shade-blend-color
This will take a HEX or RGB web color, shade it darker or lighter, or blend it with a second color, and can also pass it right thru but convert from Hex to RGB (Hex2RGB) or RGB to Hex (RGB2Hex). All without you even knowing what color format you are using