As an aside, I bought 4.5 litres of coolant yesterday from my local M-B dealer in London, and the concentrate was blue!
My original ( 2 years old) is orange/yellow so I queried the colour.
The parts guy told me that all the coolant coming out of M-B in Germany now was blue (may go greener when mixed with 50-50 water, but it's a real deep blue now).
Each 1.5 litre bottle part number is A000 989 08 25.
Hope this helps
W124 E200 Wagon 94 103,000 miles.