How can I tell the difference between an Olive (bird with 2 dark factors) vs a GreyGreen (a green series bird with the added factor grey)?
Olives have dark blue/purple cheek patches and black-blue tails. Olive is a bird with 2 ark factors. Dark factors are inherited from the parents based on how many dark factors they are carrying.
Grey-greens have silver grey patches and black tails. Grey-green is when a green bird inherits a grey gene from it's parents. In blue birds, a bird that gets a grey gene would be grey.