enhancement: ability to color icons

The specific use case is for entities that represent ink for IPP printers. I'd like to use the bar-card's icon to represent the ink color, and use the severity options to show the state of the ink level.

In case any one else is looking for this you can use card-mod to achieve that. for example like this:

style: |
  :host {
    --paper-item-icon-color: red;
  }