We know Messana is in the Tower, and that she has been tasked with sowing chaos there. I believe we were shown who she was in The Gathering Storm.

I can't recall the book (I think it was CoT or KoD), but there was a scene where Alviarin summons Messana and she sees a bit of a bronze dress when she bows with her head to the floor. That has always made me think Messana is a Brown.

Now, in tGS hardback, page 669, the five Ajah heads (Blue and Red are missing) are meeting and eventually vote Egwene to be Amyrlin. The Brown is Jesse Bilal, and I think she is Messana.

In this chapter, it is revealed that Jesse is the one that suggested the Ajah heads try to rule in place of the Amyrlin. Nothing else has created more chaos in the White Tower. Jesse is the last one of the group to agree to abandon their plan.

Then, pg 673: "We wanted women who would do exactly as we said, but instead got a group of squabbling brats with inflated opinions of themselves, too immature for more temperate minds to influence." - Jesse Bilal

So, what do you think?