Germany does not build a large navy, as a result tensions with the UK are lower and the Great War is initally a French/Russian - German conflict. Due to some reason the French and Russians do much better than in OTL, with other nations joining in as well, and Germany is defeated. The only thing they couldn't conquer, however, are the German colonies except for some small ones perhaps. At the peace negotiations Germany knows it will lose much and wants to retain the colonies for domestic politics. Besides, the French are reluctant to take on yet another colonies.
With Britain in the war, IMO such a thing would be really difficult