yaml syntax highlighting different across browsers

[gewenyu99]

Bug description

Syntax highlighting is inconsistent across browsers. Safari (ofc it's safari) displays completely differently compared to other browsers.

How to reproduce

1. the on: in version: is highlighted differently (sample link)
2. other keywords have similar issues if you browse around in safari and squint closely at code samples
3. I don't see this at all in chrome or firefox.

Additional context