It's more likely that it will just stay as white, since Apple has a "love" for their earphones being white... It's like a marketing feature, since most brands release theirs in black if Apple releases them just in white your brain gets automatically triggered to think they are Apple branded since most white earphones are.
Seems like a no-brainer to me, since Apple produces the charging pods to match the device colour. Why not the AirPods? I don't see it happening, though. Otherwise, we would have likely seen coloured versions of the lightning-based first.