WW change their coats due to temperature and light. If the hamsters were kept in a dark place before, they would show their winter coat, which is greyish white. If temperature drops, that also happens. They can change anytime as it depends on the hamster's body reaction to its surroundings. It is very normal.
Red eyes are normal. Russian campbell and syrians have red eyes but it is never and should not be seen in WW or Robos.
Why breed them? Anyway, dwarf hamsters cannot be mated like that lah. Your way is for syrian, just that you have to know when the Syrian female is on heat.

Dwarfs need to have a bond. They need to feel that they are compatible with each other to breed. Please read on breeding, your way of trying to breed them at 1st meeting in a neutral ground is wrong. They need time, it is not instant matings like how Syrians do it.