What I can tell you 100% is that the Germans will cede Japan Tsingtao and the islands they took during the war. The German foreign office, 3rd OHL, etc, all supported doing that. Sort of an attempt at a gesture of good faith towards the Japanese.
I don’t remember ever reading anything concrete about annexing French territories in the Pacific. Getting colonies in Africa was treated as a higher priority by most (with the exception of some naval officers) so the Germans might also cede Guinea and Samoa in exchange for the return of prewar colonies in Africa, should negotiators choose to press for the return of them.
Honestly it’s an extremely complex question, as the big “mittelafrika” was never really a priority. Most of the plans for colonial empire were drawn up by members of the navy, and not given much thought by OHL or the foreign office. In the Spa Conference held in 1917 by the Germans to discuss war aims, there is no mention of colonies at all if I remember correctly.
Colonies always came second to securing Germany’s position in Europe and the Ottoman Empire. It would be more likely, in my opinion, that the Germans consent to an independent Belgium in return for British withdrawal from the Ottoman Empire. Maybe Belgium would be enough leverage to snag some colonies as well though, if desired. I don’t think anyone can say for sure.
What each side considers as an “independent” belgium differs of course, and there’s the question of whether the Germans would be willing to give it up, but that’s another topic.