Some older TDIs (Passats in particular) have G11 coolant, which looks more blue than pink (G12). If your car has this coolant you should continue to use it and not mix any other coolant with it. This G11 is in a 1.5l bottle and should be mixed 50/50 with distilled water.
Warning: This product contains a chemical known to the State of California to cause birth defects or other developmental harm.