Shocked!

[careeka22]

They will lay green or brown.
There's two genes for the actual shell color white or blue. Blue is dominate so a hen can have one gene for white and one gene for blue and will lay blue eggs.
Of course brown plus white equals brown and brown plus blue equals green.
If your hens carry two genes for blue all eggs will be green.
If they carry one blue gene and one white gene about half the offspring will lay green but about half will lay brown. Because she has a 50% chance of passing the white gene forward and a 50% chance of passing the blue.
Just to be technical there really isn't a "white" egg gene its a non blue egg gene but saying white just makes it easier to explain.

Fascinating! Thanks again for all this great info. This is my first time crossing and hatching and love genetics.

 

[The Moonshiner]

It's possible that your hen had that recessive gene like the rooster and the reccessive gene from both parents got passed to the other chick, wich would affectively block the dominant one I believe.

There's no recessive genes involved. There's dominate white and non dominate white. If a bird has two copies of DW it is DW and will pass a DW gene to all offspring.
If it has two non DW it isn't DW and can't pass a DW gene to its offspring.
If it has one DW gene and one non DW gene it will be DW but will show leakage of black specks or spots because one copy has trouble completely covering black. That bird has a 50/50 chance of which gene it passes forward.
The black offspring got the non DW gene and the yellow offspring got the DW gene.