Transparent image https://jsfiddle.net/7haLkg6s/

transparentImage.html

<div style="display: flex;">
  <div style="background: yellow;">
    <img>
  </div>
</div>

<script>
(function() {

  const transparentImage = (
    h = 100,
    w = 100,
    rgba = {r: 255, g: 255, b: 255, a: 0}
  ) => {
    const canvas = document.createElement('canvas');

    const {r, g, b, a} = rgba;

    const ctx = canvas.getContext('2d');
    canvas.width = w;
    canvas.height = h;
    ctx.fillStyle = 'rgba(' + [r,g,b,a].join() + ')';
    ctx.fillRect(0,0,w,h);
    
    return canvas.toDataURL('image/png','');
  };

  document.querySelector('img').src = transparentImage();
})();
</script>