Yes, I know these forums are for World of Warcraft, but RiftUI is a ZAM site, and I'm not sure if the staff has peeked over there in a while. Therefore, I want to bring this oversight to the staff's attention:
http://www.riftui.com/forums/showthread.php?t=284
The short version is WowI has bright green (yellow? I'm colour blind) cogs for topics that are read, bright red cogs for those you haven't read yet. RiftUI's equivalent has no such differentiation, and it is impossible to tell the difference. As a side note, I'm not even sure what RiftUI's icons are; chisels, broken chalk, cracked stone?