Websites that uses the macOS tickbox selection that is using any color accent is not showing cosmetically except for graphite. Functionally it works fine.
The workaround for now is to use Graphite as your accent color.
What it looks like:
Another example on Github:
This did not occur on most previous versions of Orion. It did occur once on a old version but I don't know the version number, unfortunately.
Works without extensions?:
No.
Works with Compatibility Mode?:
No.
Does it work with a clean profile?:
No.
How it should look (on Safari):
0.99.126.4.1-beta (WebKit 618.1.2)
Mojave (10.14)