what if, the germans manage to occupy British kenya and Nigeria for example, would they be able to claim it ?
Having a Germany capable of fighting a colonial war with Britain on equal footing, being able to keep their conquests after the British ship in reinforcements and being able to supply their people from Europe (colonial forces aren't self sustaining) would require a disaster for the British as PoD. The Rohal Navy needs to be much weaker than reallife.
If Britain has its reallife capabilities, even a strenghtened CP can only get a White Peace out of them.
Also, Mittelafrika only existed in the heads of Wilhelm II and the Colonial Office. Most sane politicians would easily trade all their colonies for a slice of Belgium. Still, a victorious CP could claim the Belgium Congo, French Congo and parts of French Equatorial Africa.