The best guess I've seen from someone on MR is
Cloud services, and others have suggested it might be a data sim-only type of phone, which would work with cloud services only (no cellular functionality).
Camera? probably not
Classic? not sure what that would mean with an iPhone, but maybe?
Color? doesn't really make any sense in that it doesn't really indicate anything functionally different
China? they already have phones that are specific to the China market and they didn't designate them differently, also Apple has only ever built products primarily aimed at the US market, which they localise for other countries.
I like The-Real-Deal82's suggestion that it could all be a "Con" - that's entirely possible.
Can't wait to see if this product is for real, whether it is a 'C' iPhone and what it means. Fun times ahead.