Well, it sure looks like its going to be red! It is easy to imagine a pen full of birds that don't look red but carry red genes. Red bronze, for example, don't really look like they are halfway betwen a standard bronze and a bourbon red. They look much more like the bronze. But breed to red bronze together and you will get plenty of bourbon reds. Similarly, Golden naragansetts don't really look red, but they each have a red gene as well. Calicos are Royal Palms with a red gene. I would guess that there were plenty of red genes floating around that breeding pen, even if none of the adults looked red.