A blue or pink-violet color coolant. Up to the manufacture date of April 2014 most Mercedes-Benz engines used the blue MB 325.0 and MB 326.0 specification coolant. After April of 2014, Mercedes started using the pink-violet MB 325.5 MB 325.6 coolant specification.

 

After April of 2014, Mercedes started using the pink-violet MB 325.5 MB 325.6 coolant specification.

Typo: should be 325.6 and 326.6

The 325 series is concentrate and the 326 series is premixed, otherwise if the "dot" number (.0 or .6) is the same then they are the same. The ".6" specs can be used in the early vehicles, too.