You’re right Dave the King explanations look like old, very old diagrams. Almost looks like a bad backup after a server crash. I know I’ve seen more recent diagrams but I couldn’t find the links. I did find this —
Castling in Trice's Chess
Sort:
That was under Trice’s Chess Rules menu then If You Know How To Play Chess menu item
https://triceschess.com/rules_00.shtml
Thank you very much!
A while back I emailed Ed via the site for some corrections I had noticed (including the castling lack-of-description) but nothing changed. I'm not spam, I promise! 
I did double check. The castling page WAS in fact updated to the new blue and white squared boards. But Ed said a directory somehow got blown out and the old backup pages were restored instead of the newest ones which never made it to the backup drive. Ed asked me to pass along his gratitude in apprising him of the situation.
Could someone please describe the castling rules in Trice's Chess? I've tried to find them on the home website but I have failed and the "Castling" link on the home page doesn't lead to an explanation, just King movement.
Thanks!