It's a map of countries, not languages... There are a lot more situations in Europe where the boundaries of languages don't align with political borders.
Some other problems:
Kosovo is colored the same way as Serbia, but there are by far more Albanians live there, so it should be the colored that way.
What the hell is the color of Switzerland. Is it colored according to the Rhomansh, a language spoken by 40 thousand people, 0.5% of the population?