RGB to HEX

rgb2hex.js

const _rgb2hex = ( orig ) => {
    let rgb = orig.replace(/\s/g, '').match(/^rgba?\((\d+),(\d+),(\d+),?([^,\s)]+)?/i),
      alpha = (rgb && rgb[4] || "").trim(),
      hex = rgb ?
      (rgb[1] | 1 << 8).toString(16).slice(1) +
      (rgb[2] | 1 << 8).toString(16).slice(1) +
      (rgb[3] | 1 << 8).toString(16).slice(1) : orig;

    if ( alpha !== '' && alpha < 1 ) {
      hex += ' ' + alpha;
    }

    return '#' + hex.toUpperCase();
};

export _rgb2hex;