what is the difference between a green and blue dot?

I often look at my NewsLife window and notice both blue and green dots. In the right pane they appear with numbers in them (indicating how many unread posts there are). Similarly in the main window I see some post have a blue dot next to them and others… green. What does the different color represent?

Green dots represent unread articles that have just been newly downloaded, blue dots represent articles that have remained unread since they were first downloaded.

I know this is an old thread but I'd like to ask: what defines "newly downloaded"? ie. when does a green dot turn blue? I think this is an awesome feature btw

Basically after a feed download occurs any unread articles will be coloured green. If the articles are still unread after the next download or after relaunching NewsLife then they will be coloured blue. So basically only the 'freshest' unread articles are green if that makes sense.