Hello! I'm a long-time player coming back from a very lengthy break. A lot of things are new to me, but thankfully I've been to figure most of it out. However, I've noticed some users have a blue or yellow aura around their avatar, specifically in the avatar preview view. What is this color aura?

They're avatar borders! It's a feature that they recently added, that I'm assuming will be more prevalent as they continue to work towards the updated site layout.

The two you're seeing around were prizes from the most recent Quest-A-Thon

Good to know, thanks! I think they are cool and I'm excited to see what they'll do with them next.