Why are Sonic's eyes green in Sonic Adventure, the franchise's first serious crack at a fully 3D polygonal platformer? It turns out there's a lovely little story behind that. Ristar creator Yuji Uekawa was the man tasked with revamping Sega's mascot for his debut on Dreamcast. Some of his decisions were practical: shrinking Sonic's enormous, swept-back skull and elongating his limbs, for instance, so that he doesn't look like a fuzzy joystick when viewed from the rear. Others were a touch more poetic. "He is always seeing these green pastures around him, like in Green Hill Zone," Uekawa explains in an interview conducted for Sega's 25th anniversary artbook. "I thought it would be nice to reflect that in his eyes."
You can imagine the scene. A high-powered SEGA meeting, somewhere in a Tokyo high-rise. The brass is gathered, and PR and marketing representatives for each territory shuffle notes and try not to look each other in the eye. They're here for the internal announcement of a new Sonic title. Hopes are not particularly high.