Parrotlet Eggs

[bebs.]

My p'lets have eggs but I've noticed that one of the eggs are getting darker each day. (turning into a grey-ish shade)
I've read a lot online about the problems in eggs but could not find an exact answer to this problem.

Could it be dead-in-shell?

I don't know if I should remove it or not. It is their first clutch and I know some of them might not be fertile just by looking, (some look more yellow than others) I didn't want to take any eggs away knowing that she'll be laying more and more so I left the infertile eggs with the hen for now.

[chapala]

I'd leave the bad egg until either the others hatch, when you can remove it, or if none hatch, when she loses interest in the eggs, then all can be removed.

[Tony Bucci]

You can candle the eggs without touching them. Use a penlight and just bring the light next to the egg.( Providing the hen will let you). You can tell if the egg is fertile after she sat on them for 5-6 days. Internally the fertile egg will appear reddish with visible blood vessels. The fertile egg at the later stage will appear darker and darker until it is no longer transparent. At this stage you can't tell if it is dead in Shell or otherwise. If you are brave enough you can float the eggs in warm water. The fertile ones will faintly move in the water the infertile ones will not move. Don't leave the eggs in the water too long. This method will soften he shell(in case of dry climate, it will facilitate hatch-ability).
The infertile eggs internally will appear clear, yellowish, transparent, If you don't feel to do what I suggested, fallow the suggestions Reta gave you.
Tony

[bebs.]

Thanks a lot for the feedbacks!