For anyone who wasn't sure how to tell one court from another... here's your answer. It's the color of their eyeballs. Black eyes like Gavin's denote Winter Court while white eyes denote Summer. Fey that don't owe loyalty to either court may have colors other than white or black - though many seem to choose white.
The Summer Queen has colored eyes - hers are yellow - but she's the queen so, she gets away with it. Seriously, who's going to tell her no? I sure as hell ain't.