Kairi's hair in that scene sometimes looks more red in some pictures/gifs than others so I think it depends on quality and such (though Nomura seems to be trying to make her hair more brown for some reason). Quiet frankly I'm surprised that Nomura hasn't taken advantage of SRK's home beach setting to have the characters in swim suits yet.
Though speaking of Kairi, this was one of the first official KH2 images of her:
and there was so much debate over it because it wasn't said it was actually Kairi. For weeks people debated yes, most actually said no, the ones who said yes argued that it was her because of the red hair and that she had a bag because she was going to run away and look for Sora and Riku (not all that far off the mark). The ones who denied it was Kairi said it couldn't be her because she was too "womanly" and her clothing was nothing like her style (because apparently a lot of people don't know what a school uniform looked like) and that she wasn't standing in her "Kairi pose". Then there were the "it's Kairi"s sister!" debates. The picking apart of this particular image was amazing.