Safari supports text fragments, but it does not support the ::target-text selector to style them yet. Here's a side-by-side comparison of Chrome (left) and Safari (right), using the demo linked towards the bottom of the MDN page:

That’s not true. The only difference in the automatically generated screenshot example is the color of the highlighting.

Uh...yes, that's exactly what I'm trying to show. The color of the highlighting (and the text color) is exactly what shows if ::target-text is supported. The example page has the following CSS:

::target-text {
  background-color: rebeccapurple;
  color: white;
}

We can see that in Chrome (left), the background color is correctly set to rebeccapurple, but it is not in Safari (right).

Will anyone see and respond to my latest comment, now that it has been automatically closed?

Oh, now I see. Sorry for my misunderstanding. I was unaware of the color specification. Thanks.