benedict XVII said:Congo is not Belgian in 1901!
Ummm....okay, apparently you haven't noticed that these maps show control which is why even occupied countries are coloured with the same colour as the occupier, so calm down. Whilst in a perfect world we would have 10,000 ways to show this while using pixels and Microsoft Paint, in OTL we can't. Besides, what is the difference between Congo sharing the same head of state as Belgium and being treated as a personal fief of Leopold II and Congo being Belgian? And how are we going to show the relationship of Congo and Belgium having the same head of state if not by using the same colour? Also when Belgium annexed Congo is not relevant in light of the fact that Egypt was never formally a British protectorate until 1914, but it wouldn't be accurate to colour Egypt as being solely Ottoman until 1914.
Annexation of Luxembourg is only in 1941
Actually Luxembourg was never officially annexed. Yeah, it was occupied and its constitution voided (1940), it was administered as a part of the Gau of Coblenz-Trier (from 1940) and its citizens were granted German citizenship (in one form or another) in 1942, but never was it officially annexed a la Sudetenland. Hence I include it from 1940 since it was administered de facto as part of the Reich from 1940.