It's not unusual for them to start turning blue on day 2-3. The first 5 days are the "scary period". After 5 days, if they're still white and fluffy, then generally, they are fertile and have a good chance to make it to the end, assuming that the environmental conditions are right. The first 5 days are all about observation, crossing your fingers and hoping for no unusual colors.

Good luck with all the rest.

Tom