Yes.
As far as them breeding true, I should have clarified. Not the birds, egg color, does green egg color breed true?
Not really. You have a dark brown layer and a blue layer, put them together, and you have a bird with partuial genes for each color. From there, wherever you breed it to, its genes and the other parent will follow. If you really want to though, you CAN make a true breeding green type color, but it takes much patience with hatching and testing a lot of F1 x F1 girls.
I guess it is not relevant as he was the lone hatchling and I don't have an olive egger to breed him to...so just for curiosities sake? So OE x OE = a similar shade of olive egg? OE x dark brown egg layer(i.e.Marans type) = darker green egg? OE X Blue egg layer (i.e. true Ameraucana or Araucana type) = lighter green egg? Do they always combine like that or will some from a cross like that still only lay brown or blue eggs? What would breeding to a white egg layer do to the egg color? (Nothing?) I'm sorry if this has been discussed before...I haven't seen it. Thank you for your patience all
OE x OE, first gens, will create anything from the original blue parent's blue to the original dark layer parent's dark brown to normal brown to normal green to a serious dark greenish gold to a serious dark green and everywhere in between.
OE x dark layer = darker egg yes, however it's a little less "green" but still seriously awesome in color.
OE x blue layer = more greenish blue of an egg. Slightly lighter yes, but more blue really.
Here's a chart I did a while ago -
White egg layers added lightens the egg color without changing the hue.
The chart is a little outdated for my info though, as I'm sure a OE x OE creates a huge mixture of egg color opportunities.