00 06/04/2012 22:15
Danny, I thougt to an I allele because from my platenbonts time ago were born some chickens with that colour. And if were not for the I gene, also platenbonts would blacks as your adults.
(Looking the photos the chicks seems not a blue, I asked about it because, as you have noted (time ago), sometimes blue chickens seems black. But I am sure you checked them.)