Weird dark colored eggs

[LavenderDaFlerf]

The past three day my one of my ducks has been laying grey eggs when I have always only had white one, any ideas on what could have caused this? The white one is for comparison.

 

[JacinLarkwell]

It's just the bloom. Some lay charcoal eggs

 

[LavenderDaFlerf]

It's just the bloom. Some lay charcoal eggs

But can this randomly start happening after the ducks have been laying for months?

 

[JacinLarkwell]

But can this randomly start happening after the ducks have been laying for months?

That I don't know. I know the charcoal eggs can get lighter as the season goes, but I've never had any that lay that color myself