The following information is the way Marluxia appears in all of the games related to the Kingdom Hearts series. Not much changes between the games other then the images of him that are out.

Marluxia is regarded as a tall, elegant Nobody with feminine features. Marluxia wears the basic Organization uniform of a black cloak, black boots, and black gloves. His hair is shoulder-length and rose pink with ruffles, though in the Gameboy version of Kingdom Hearts: Chain of Memories this color was more muted, appearing closer to light brown. Marluxia's eyes are blue and his lips are pale pink.

Marluxia is usually surrounded by cherry blossom petals, which symbolize the transient nature of life and death in Japanese symbolism. Marluxia drops these petals whenever hit during battle, and fades in a flurry of petals when he is destroyed.

I also think it is important to notice that Marluxia was originally suppose to be a female in the first sketches for his character. The creators decided it would be easier to have a male character try to betray the Organization so they switched him to have a more manly-look. They decided to keep the pink petals and his pink hair, and the decision to have him walk and act a bit girly. It is also hinted that Marluxia is not gay when Axel points out that Marluxia will have nothing to do once Larxene died.

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