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the genes for pea-comb reside very close to the blue egg gene, so they are commonly inherited together
When referring to colored/ tinted egg layers this is true to a point, but there far more breeds that have a pea comb that don't lay blue eggs than there are blue egg layers that have...
Depends on the cross that made up your birds, you can get/have Blue egg laying hens with single comb. A good xample of this would be a Cream Legbar.
Blue X Blue = Blue
Blue X White (eg, Leghorn) = Blue
Blue X Brown (eg, R.I. Red) = Green
Blue X Dark Brown (eg, Maran) = Olive Brown
Chris