Some color conversion functions

ColorMath.js

// converts 255, 255, 255 -> #ffffff
export function rgbToHex(r, g, b) {
  return '#' + to_hex(r) + to_hex(g) + to_hex(b);
}

function to_hex(color) {
  return color.toString(16);
}

// converts 255, 255, 255 -> #ffffff
function hex2RGB(hex) {
    const r = parseNumber(hex.slice(1, 3), 16)
    const g = parseNumber(hex.slice(3, 5), 16)
    const b = parseNumber(hex.slice(6, 8), 16)
    return { r, g, b };
}


// computes brightness of the pixel
export function luminance(color) {
  return 
    0.2126 * color.R +
    0.7152 * color.G +
    0.0722 * color.b
}