There are no current rumors at this point. Apple will likely expand colors, as they usually do after the initial release. Black seems like a strong possibility.
im gonna say there will never be black airpods. They never made black earpods. Also, they are probably using a lot of the materials they use for the earpods that come with the phone and leverage them to make the airpods as well.
i would need to see a final product review first. Also, i would be very concerned about longevity and durability if they are painting on top of apple's coat and sealant.