Read It by email@example.com in pipedot on 2014-05-13 09:55 (#3KF) Ever revisit a popular story page and wish you could easily distinguish the new comments from the stuff you've already read? Well, now you can!New comments are now shown in blue, while old comments are shown in gray. Simple enough, right?
If you reply to a post at the top of the thread, before reading the whole thread, then when you return to the thread after clicking "post", all those things you've not read are greyed out.
I presume this is just timestamp-based? If so, perhaps don't commit the "thread last rendered" timestamp until some affirmative thread-leaving action is performed. Posting a reply would not be classified as a thread-leaving action. This might require some significantly trickier smarts to implement than just the naive situation we have at the moment.
Simpler Workaround: middle-click the "reply" link to get it in a new tab, and then just close after posting.