css颜色rgba转16进制

rgbaTo16color(color) {

  let val = color

    .replace(/rgba?\(/, '')

    .replace(/\)/, '')

    .replace(/[\s+]/g, '')

    .split(',');

  let a = parseFloat(val[3] || 1),

      r = Math.floor(a * parseInt(val[0]) + (1 - a) * 255),

      g = Math.floor(a * parseInt(val[1]) + (1 - a) * 255),

      b = Math.floor(a * parseInt(val[2]) + (1 - a) * 255);

  return "#" +

    ("0" + r.toString(16)).slice(-2) +

    ("0" + g.toString(16)).slice(-2) +

    ("0" + b.toString(16)).slice(-2);

},