They look very young. Could the silvery stuff be from inside the egg? Usually a light scrub with a soft bristle toothbrush removes it while they are soaking.
Perfectly normal shell color.
The white stuff on the scutes could be one of two things:
A) Residual fluid from the egg that has dried on the shell and this happens all the time. It will wash off in time.
or, B) Sometimes the hatchling pips the egg a little prematurely and air gets to the hatchling before the shell has completely hardened off. What then happens is that portions of the shell dry out and shrivels a tiny bit leaving those white areas. But all of the new growth that the tortoise lays down in the future will be normal looking. The affected places will look that way until the tortoise eventually wears it down. In NO WAY does it harm the animal and by the time the little guy in the photo is half grown you will not even be able to see these places.
It is possible that it is some form of shell fungus but I doubt it.
Not sure if this is the same, ours have a slight film when they are fresh out of the egg. Usually comes off after the first soaking or two, never permanent.