How can I "make" an olive egger?

[McChooky]

Something strange that I’ve found, in my flock at least, is that if I cross a blue egg roo with a brown egg hen, the eggs stay blue. But if I cross a brown egg roo with a blue egg hen, then it’s more green.
I still don’t have an olive yet, though.

I only raise smaller breeds because I like to free range. No marans or bigger breeds.