You’ve had good advice above
. How old are the babies now? Let us know if you have any problems sexing them when they’re ready to be separated. I agree that for diet it would be best to assume they are hybrid - so a sugar free diet. There are sugar free hamster mixes available- but any that contain fruit like banana chips still have sugar (it just doesn’t need to be declared on the packet - only the ingredients have to be declared, not the contents of the ingredients). Most banana chips are sugary. Veg is fine but not fruit really due to the fruit sugars.
You could contact the breeder and explain you’ve had a litter and ask him for details of the pedigree line as you will need to find homes for the babies. As a kind of way of finding out of the breeder does know a pedigree line.
There are a lot of hobby breeders around who don’t always know much about breeding and pedigrees.
Which country are you in?
There’s some info with photos on this web page about winter whites and the colours
Dwarf Hamster Varieties - Harvey Hams