[Sokka has a lot of feelings about the color blue, and generally speaking, so do a lot of the people he's encountered over the past year, for a lot of reasons. To just — shrug it off, like there's no weight or meaning behind wearing it, disorients Sokka more than a sudden attack would.

On top of that, the name question is hard, in that Sokka has no idea if he should make up a Fire Nation name or give his own. He doesn't have enough information about this place to make any informed decisions, so there's a brief hesitation in which some uncertainty leaks through, before it hardens into determination again.]

I like blue. Blue's great. I wear blue all the time. I was wearing it before I got here. I even dress my flying lemur in blue. [He says it with an air of sarcasm — and challenge, even though most of what he's saying is true. He figures that if this is some kind of trap to get him to confess to being affiliated with the Water Tribe and the failed attack during the eclipse, this is the best bet he has for testing it.

That, and:]

And my name's Sokka.