Damn it. I was really hoping they were secretly going to launch with assorted colors, not just plat/black like they briefly tried to pimp with the GBA "Limited Edition" model.
Sega released colored versions of the Game Gear (I used to own a blue one that came with Sonic 2, and I distinctly remember a red one for a promotion of a Japanese Coke game. There was also one encrusted with diamonds-I shit you not, although that might have been a private make), and I know the Dreamcast came in red/blue (Code Veronica), Black (Sega sports), and pink (Sanrio promotion.)
DS preorders are already sold out, they're going to sell through every single plat/black DS they make at launch. They'll release new colors once sales begin to settle down. Basic business.