Use the `sd-footnotes--inverted` class when displayed on primary background.

```html
<div class="px-12 py-8 bg-primary">
  <ol class="sd-footnotes sd-footnotes--inverted">
    <li>Lorem ipsum dolor sit amet.</li>
    <li>Sed diam nonumy eirmod tempor invidunt ut labore.</li>
    <li>Dolore magna aliq erat, sed diam voluptua.</li>
  </ol>
</div>
```