6-bit RGB is a regular colour palette which provides 64 colours. Having a two number colour code limits us to 100 (00 through 99) possibilities. Keeping the first sixteen the same, we could still add 64. Whether the original 16 would be in those 64, who knows? But, we could map those 64 colours accordingly, and in such a way that clients which already map those colours to the original 16, will be matched close enough.
