White (REW I assume) is a recessive that "covers" other genes. Most likely it is an agouti which carries self from these colors. I understand that many NZW are. The red would also be an agouti that also has a "tortoise" gene. @Bunnylady correct me if I am wrong?
Don't forget about Steel. Steel + normal extension = classic Steel, but Steel + anything else in the E series can be solid black, like a self, even if the rabbit has Agouti genes. It looks to me like there is at least one obvious Steel in that litter; the solid black babies may develop ticking as they get older. Reds can't carry Steel (because Red requires two copies of the non-extension gene e), but the other New Zealand colors frequently do.
Sorry folks... right clear over my head. I have no brain function to handle genetics... Just not passionate enough about it to want to strain the brain cells. My level of genetic knowledge is along the lines of; OOOOooooo look at the pretty colors!