Community of Sexsoundlovers

Hi all,
I just was wondering about the function of the icons in the list of topics.
There seem to be two types; one could be supposed to be „text“, the other might be a flame or fire. They appear in two colors: grey (what could be interpreted as „no color“) and red.
Anyone has an idea of the plan behind it?

All the best…

grey text: no unread messages in this thread
coloured text: unread messages in this thread
flame: same meaning but postings with a certain amount of replies ... so these postings seem to be "hotter" than the ones with the text icon.

Thanks again.