User blog comment:Sorairo/Aura, Dust, and the RWBY Panel/@comment-11188061-20130823055451

Yep, pretty good breakdown. Speaking of which, you can compare Yang and Crimson's eyes together if you want.

When Yang overloads herself with Aura her eyes turned Red. However, she became normal again when she doesn't use her Aura.

Whereas Crimson's eyes looked to be permanent Gold (we can assume as much from the opening). Of course, it may not be Gold as of now (over the Episodes Crimson slowly changes who she will become, if you know what I mean), but it will be in the future. That is probably a sign that a person has became an Aura Master, or perhaps that she has stepped into a forbidden territory of Aura and acquired incredible power, with the change in her eye color as proof of that.

Now that I think of it, it's perhaps not too farfetched to think that the girl in Yang's picture (Yellow Trailer) may be Crimson. They share a common feature, and Yang may have wanted to inquire her further about it. This is a complete guess of course.