Thamnophis marcianus - babies with yellow stripe

[ConcinusMan]

It's interesting that albino babies have yellow stripe along along the back...

Most garter snakes do.

Also some of them has pattern on their heads, is it normal too?
Attachment 10376 Attachment 10377

Nope. Those are "pastel" morph, which is thought to be codominant or incomplete dominant. It can vary widely in the degree of expression but it almost always affects the head pattern in some way.

[Jeff B]

Where did you get the parents?

[Rebekka]

I've bought them in Moscow and I don't know any details about theirs origin.