hex to rgba

hex2rgba.js

(str, alpha) => {


    if(!/^#([A-Fa-f0-9]{3}){1,2}$/.test(str))
      throw new Error('Bad hex')


    let c = str.substring(1).split('')
    if(c.length === 3) c = [c[0], c[0], c[1], c[1], c[2], c[2]];
    c = '0x'+c.join('');
    return `rgba(${(c>>16)&255}, ${(c>>8)&255}, ${c&255}, ${alpha})`;

};