Wouldn't the green eggs be O/O,P/P right? When you put them together and all?
So white would be o+/o+,p+/p+
Blue would be O/O,p+/p+
Brown would be o+/o+,P/P
is that right?
I would leave the brow egg shell gene trait as unknown polygenic and don't assign any symbolic genetic name or number.
Source: https://academic.oup.com/ps/article/94/10/2566/2077496 (Genetics of Egg Color section)
Summarizing the genetic work conducted, it can be concluded that the genetics of the brown eggshell color in the laying hen has not been studied sufficiently to understand the process of shell pigment synthesis in the shell gland.