Von

Ok… honestly i have always payed attention at diameter/thickness and weight, but seeing them now make me question myself about colour. 
 

a friend if mine noticed the same on some krugs he have. 

Hello, looking at these coin, i have a doubt and im a little worried, because both have diameter/weight/thickness in the specific, but even if of the same type and year, they show different color: one the usual pink/red one, the other a bright yellow.

Opinions?

thanks and sorry for my bad English…