Smooth as Silk
We want to include kimono as an image because…well, they're super pretty. If you need only one reason to watch the film version of the book, it's to see the gorgeous kimono. They're so amazing we'd consider trading in our usual cozy uniform of sweat pants and a hoodie for the discomfort of wearing yards and yards of intricately arranged silk.
Just check it out: Hatsumomo's kimono, a water-blue garment with silver fish and gold trim, is "lovelier than anything [Chiyo had] ever imagined" (3.56).
But kimono aren't entirely for visual pleasure. One bit of historical trivia that you may not know is that kimono are incredibly heavy. You'd think something as thin as silk would be light, but geisha must build up their strength to be able to wear them. Plus, the obi, which is the sash around the kimono, adds to the weight.
The main significance of the kimono, though, is as a status symbol. Chiyo starts off wearing rags, and as she climbs the ranks to become one of the most famous geisha, her kimono get more and more beautiful. They also serve to differentiate ranks within the okiya.
The apprentice geisha generally wears more colorful garments because, to put it bluntly, she is being shown off to men for sexual purposes, like a peacock showing off to a mate. One businessman even tells Sayuri, "I believe the apprentice geisha of Gion is perhaps the most brilliantly colored primate of all" (14.15). If geisha are animals, the kimono is their pelt.