Disclaimer: I don't own Kingdom Hearts nor will I ever.
They Wear White
When Kairi was little she was obsessed with fairytales. Both Sora and Riku can attest to this since they were forced to play along. Forced may not be the right word, once they got into saving the princess and vanquishing evil they forgot they were supposed to think it was stupid. Kairi played the part of the princess in her little pink dress, Sora the prince with his bravery his greatest weapon, and Riku the knight who helped the prince out of problems Sora caused.
As they got older the games stopped. The parallels of good and evil remained. The princess was in real danger of losing her heart forever. The evil doers weren't silly sea turtles. The prince could fight for himself and solved problems more often then he created them. The knight wasn't necessarily as good as he once was. Nor was he looking out for the prince anymore.
Another thing that changed was that their perception of good and evil changed. It was harder to tell who the bad guys were, who had just lost their way, who were trying to get their loved ones back the only way they knew how. Telling who was good wasn't easy either, who was doing things for the wrong reasons, who would turn out to be evil, who lost their hearts along the way. Sometimes it was just bad actions done by good people. Evil people who started out with the best of intentions.
As Sora slept the lines between good and evil blurred even more. So much so that a young witch named Namine couldn't really tell them apart anymore. That's not to say she didn't try though because she did, often. Books she got a hold of from the library told her that the good guys wore white and the bad black. Although that didn't make sense to her. For the most part, she didn't think the members of the Organization were bad people. They just wanted their hearts back, to be someone again.
Demyx didn't like doing bad things. He avoided fighting at all costs. In fact he requested missions where all he had to do was scout for information or retrieve items. He was the happiest when he was left alone to play his sitar. The few occasions Namine had had the pleasure of interacting with him showed that he was a complete sweetheart. All he ever wore though was a black cloak.
Roxas couldn't be bad; he was a part of Sora after all. He didn't want to be rejoined with him though, he wanted to be his own person. He left so he wouldn't cause complications for Axel even though he ended up hurting him in the end. Roxas looked out for his friends even the ones he made in Twilight Town.
Axel definitely couldn't be evil. True he looked out for himself most but when you're so high amongst the Organization you kind of have to. Really though he knew what was going to happen to all of them, that they wouldn't all get hearts, especially once Sora woke up and was after them. All he wanted was his best friend back.
Namine watched as Sora slept through his memories being put back together. He was the hero in all of this. He didn't exactly wear white, his jumper was mostly red with little bits of white. He was the best hero she had to go by.
Namine really liked Riku. He was so kind to her. He had made some questionable decisions in the past and was labeled the villain because of those decisions. He locked himself within Kingdom Hearts to save his friends. Ran around the Castle trying to find Sora. Hid his eyes because they couldn't lie. Helped Sora and Kairi at all costs. Yet he wore the black cloak that was supposed to signify that he was one of the bad guys.
Namine knows she isn't as innocent as she appears. She helped construct a whole fake world to fool a boy before his life was destroyed. She made duplicates of good people to fill the town. She rewrote Sora's memories the deeper into Castle Oblivion he went. She tried to erase Kairi to put herself in her place. She saw the shattered look on Roxas' face when she told him he was never supposed to have existed. She trapped Sora in his sleep-like prison. She is the one they call a witch.
She wears a white dress with white shoes, the usual color associated with good. She knows that people think she has the face of an angel. Sweet eyes and shy smile that could never harm anyone. Her entire room is sterile white. It honestly drives her insane. She fills her sketchbook with anything she can think of. Drawings of Sora, Axel, Destiny Islands, Roxas, herself. As soon as they're done they're ripped out her sketchbook and taped to the walls. Littered over the white floors, covering the white table. Anything to hide that damned color that mocks her.
Namine believes she can tell the difference between heroes and villains now. Sometimes it's harder to tell, such as in the case of Riku or Ansem the Wise. She knows now though that the villains wear white.