All of them are mixes. They probably do have Netherland Dwarf in them though. From Moonshadow's response, they do look like they could be mixed with the Dutch breed.
The grey one's color is called Chinchilla the white implies that she/he has the Vienna gene (blue eyed gene) does he/she have "marbled" eyes (a mix of blue and brown kind of like the human hazel eye color). The white one with the eye circles looks like she's a Chestnut Vienna (You can see she has the marbled eyes). Are the spots more brown or more black? The last two are Black Vienna (that is if they have the marbled eyes).
I would recommend against breeding them, especially if they all are related. There is already and more stock of rabbits due to over breeding of lots of mixed breeds. When animals are mixed with a ton of different breeds, their genetics get wonky and they are more prone to sickness and genetic problems (bad feet, bad eyes, etc.)