Some forum posts greyed out?

[Randall_Lee_Reetz]

What causes this? What does it mean?

[rms]

If you mean like shown in screen shot, it means you (or your computer) have read those posts. It’s not another bug.

[AmberV]

Yes, if that is what you mean, they will light back up once there is something new within them to read. Grey means you have no reason to go back for now, unless you like re-reading.

[reepicheep]

Or do you mean the hreying out of this post?

But I think that is self-explanatory.