I think it is common mistake because some people do not understand the origin of CsW.
Yes, there are different colours by "new" GSD (because many GSD living now are more or less mixes of different breeds). But it do not aplly to our breed.
By for making Czechoslovakian Wolfdogs were used ONLY WOLFGREY colored German Shepherds:
They were dogs coming from the old DDR lines which were PURE (not mixed with other unknown breeds so there were not liver, merle or any other "strange" colours).
Do not also compare CsW to Saarloos - one more time: the DNA test show that Saarloos are NOT (pure) wolf x GSD crosses. They are crosses of different breeeds - they are not mixes but mutts. It is why you can meet there some really strange dogs with all possible colors. The other breeds were added by Saarloos but also later there was a lot of pedigree cheating by Saarloos breeders.
Till now Czechoslovakian Wolfdogs were free of such cheating. Because of it there are NEVER born any liver, white or black Wolfdogs. Because such genes to not EXIST here. In the 30 years not even one such case was born in the "pure" lines in CZ and SK (and by breeders which breed pure CsW).
So if you see any "strange" Wolfdog the ONLY explanation is that it is nore PUREBREED dog. Not a mutation, not a "genes from the past" - but because of not pure blood added tosuch dog.