Some Euros do use a blue coolant. I have several BMW's and their OEM stuff is blue. It's phosphate free coolant to help not get the corrosion in the aluminum parts of the cooling system. I use Zerex G-05 phosphate free in all of cars (gold/yellow color). Same principal, just half the cost.

As a side note: Every BMW I have had the regular green coolant in it when I got it (all of them are 15-20 years old when I get them), so with regular flush and fills this is fine also. Just don't ever switch to the Dexcool orange stuff!