Here
The blue with stars indicate an unopened thread with the number of posts next to it.
The green with a number in it indicates a previously opened post with the number in green being the total new posts since I last opened it and the overall total in the whole thread to the right of the green.
The grayed out box with the number "0" in it indicates a thread that I have opened with no new posts since the last time and the total post in the whole thread to the right of the gray.
Hope that helps