Minor feature request: Chequerboard/artboard background for white assets with tr...

Can I request a Photoshop style background for user uploaded img instances in the admin area (eg. .grid-asset img).

When uploading images with a transparent background that are exclusive white it's impossible to see them.

I currently append the style.css sheet, but it's a pain to remember to append it again when replacing the core.

eg:

.grid-asset img {
  -o-object-fit: fill;
     object-fit: fill;
  display: block;
  height: 150px; 
  background-image: url(../img/artboard.svg);
  background-repeat: repeat;
  background-size: 16px; }