Most Western countries who had colonies have some very dirty historical hands, and this dirt often takes the shape of massive wealth spent on elaborate monuments, buildings and public works back home.
Ironically, the Germans was actually more or less the "good guys" in Europe before the 20th century, as they relied more on their own productivity and trade rather than the colonialism undertaken by the British, Dutch, Danish, Portuguese, Belgians, Spanish etc.
Of course, Germany - previously a patchwork of Imperial estates and duchies in the (neither) Holy (nor) Roman (nor an) Empire - didn't become a single country until 1871.