MyBB Community Forums

In my themes imageset there is on.png and off.png for the forum markers (read and unread).

How to make it so each forum shown on the main page has it's own unique image that doesn't change regardless of new posts in that forum?

1.) Your question has not recieved any answers yet because your question is too broad.

2.) There may be a plugin for that.

3.) If you edit the index template you could add your own custom images using the <image src="#" /> tag