meaning of colours and symbols in forums and posts

Hello,
why are some posts gray and other green (same for topics)? Also there are different symbols used.

See picture here https://pasteboard.co/IQXLzSE.png

Is there a legenda somewhere?

Hello,

Gray color posts means that you viewed the thread, Green are new posts. FYI, this forum is very old and will be replaced with a modern platform in the near future.

Best,
Tom