Can't customize button color

[spencerpro]

I wan't to change button color, like the buttons used for tags, but color code for taxonomy. I see the color in the page source, but no matter how I set the color, the button is always blue. However color change works if I set the background color.

eg.

<a href="/session/2022-11-29/" class="link f5 grow no-underline br-pill ba ph3 pv2 mb2 dib red sans-serif">

still renders blue