Customised colours - Back link example

index.html

<!-- This code example is not the same as GOV.UK Frontend, and is just for demonstration. -->
<style>
  .back-link::before {
    content: '';
    display: inline-block;
    margin-right: .3em;
    border-top: 0.3125em solid transparent;
    border-right: 0.375em solid currentColor;
    border-bottom: 0.3125em solid transparent;
    clip-path: polygon(0% 50%, 100% 100%, 100% 0%);
  }
</style>
<a href="/" class="back-link">Back</a>