Plot hole: There is supposed to be no power when the Dragonfly ship reaches the island, but the lights are still on. At first, I thought it was just a lighting trick, but you can see the lights are on in the tunnels.
Plot hole: When Carmen is undercover as a pop star at the end of the movie,the crowd was cheering her name(Carmen). If she's one of the top spies, she would know not to use her real name if she was undercover.
Answer: Her sock colour is most likely black during that scene as it was when they were in the treehouse.