How exactly do you get to the live chess tab?
Highlighting squares

Then there must be another way, since I still see the streamers mentioned above doing it to this day, I don't get how.

Then there must be another way, since I still see the streamers mentioned above doing it to this day, I don't get how.
As far as I'm aware, the old interface has been retired. Any link to a stream where it's currently in use and someone isn't just using custom client-side CSS to change colors?
How do you change the color of highlighting? No, not the shift or ctrl ones.
When I highlight squares, it's an orangish color, but when streamers like Gotham or Hikaru highlight, it's a much darker, red color. How do you change the default highlight color? I don't see any setting for it.
You can't change the hue. There is however, a difference between the Live Chess and Play interfaces.