Incubating eggs turning brown

[OzarkCountryGirl]

I have an incubator full of quail eggs with a wide range of shades and patterns, but some of the eggs look to be turning a darker, yellowish brown. Is this typical? With chicken eggs that usually equates to a rotten egg, but this is the first time I've tried hatching quail eggs. It's just that it's 4 days until lock down and I don't remember some of those eggs being so dark...

 

[Quail Jailer]

For what its worth, I've never noticed one getting darker.

 

[Dragons4u]

Did they get something on them, like goop from a broken egg?

 

[OzarkCountryGirl]

No, nothing spilled. I was just curious as to if that meant the eggs had turned rotten and a bit wary of having exploding eggs and all that. I didn't candle all of them when I put them in, as there were over 100 eggs, but rather just randomly candled, of which I did find two with cracks. I candled a couple of the ones yesterday and didn't see any cracks or leaks, and the lighter air cell was easily detectable from the dark mass. I didn't look long enough to notice any movement, though, which would probably be hard to see in quail eggs anyway. I'll just wait and see what happens, and make notes of it in my records.