Essentially Germany would not have the means to force a peace on own terms against Japan and China (if China) is at war with Germany
I also doubt that Germany could "force"conditioons to the Dominions (which held some of the old German colonies)
To determine what happens you first have to clarify how the CPs won... - All nations at war with Germany will get their separate peace treaties - there will be no JOINT "Entente" defeat...
Assume they win on the Battlefield Russia and Romania are taken out as OTL...
assume further that GErmany somehow takes out France and Italy - thats all that Germany realistically can do. It can't occupy UK (Sealion - not even with the Hochseeflotte IMHO
)
So the Scenario is probably a victory on the continantal Euriope and a strong position (troops for Turkey) in the Middle East.
Basically French and Italians ask for peace and UK says I can't fight Germany alone, but I am also save from Germany.
We get harsh terms for France and Italy
Germany would ask to get back the colonies, but that would require something to trade off
Japan and the Dominions would tell Germany come here and take what you want, but we won't give it to you.
UK might be forced to put pressure on them but in reality is probably more inclined to say those are independent nations.
As Germany probably also wants to end hostilities would try to make the best of the situation. Maybe - to save face - a moderate sum has to be paid by Japan and the dominions for the colonies. They keep them and germany can say : we have NOT lost them - we traded them away.
African Colonies are probably more digfficult. France certainly would have to give up its share of Togo and Kamerun. As OTL Germn east Africa had not surrendered it will be most likely stay German and probably the Brit occupied parts ot Togo/kamerum will also go back.
But Deutsch Südwest will probably also be traded. (to South Africa)
Germany might also want some French/Italian/Belgian colonies (Kongo most likely)
If Germany is hard on frnace - french Indochina might become German Indochina - which in turn might later spark German ambitions to regain its Pacific posessions... This certainly would have an huge impact on China and Japan.
IF (likely) the US never intervened japan and UK will stay on good terms to secure their "Chinese" (and indian/Korean) posessions.
GErmany might - as OTL - try to get a foothold in China economically without being a colonial power.
While Japan leans to UK China and Germany will grow closer. (OTL UK and Japan became enemies and GErmany grew nearer to Japans and dissolved ties to China).