That's one of the many questions we asked Beth Llewelyn today. When will we see the orange GameCube?
Actually, it's a big unknown. There's no plans of releasing the Spice GameCube in the US as of yet. The spice controller will be available at launch in the US, but so far Japan is slated to get the Spice GC sometime in November. The US and the rest of the world may just get indigo and black.
Beth did say however that other system colors could be released later on in the GameCube's life. But for right now, the US will be getting indigo and black for launch.