[data-swatch]::before {
  background-color: rgba(var(--text-color) / 0.08);
}

[data-swatch="black"]:before { background-color:#000}[data-swatch="white"]:before { background-color:#fff}[data-swatch="gray"]:before { background-color:#ccc}[data-swatch="red"]:before { background-color:#fd0a0a}