The simplest color tone function for JS
npm i make-tints
import {tint} from 'make-tints'
const tintBy = tint('#000')
tintBy(-20) //=> 000000 darker tints can be achieved by using negative percentages
tintBy(20) //=> 333333
tintBy(40) //=> 666666
tintBy(60) //=> 999999