A function that calculates if text color should be black given a background color. (W3C compliant for all values)

textColor.js

function useBlack(r, g, b) {
    const e = v => Math.pow(v / 255 + 0.055, 2.4)
    r < 11 ? r /= 15496 : r = e(r) / 5.348631
    g < 11 ? g /= 4606. : g = e(g) / 1.589931
    b < 11 ? b /= 45631 : b = e(b) / 15.74957
    return r + g + b > 0.17912878
}