Absolutely. Unlike mammals, bird siblings can and will mate without the genetic anomalies (i.e., birth defects). If there is a birth defect it is either going to show immediately, decades down the road or never. Usually, we do see some variations in color which can be considered a defect, but nothing to suggest that the coloring is going to be detrimental to the birds' health.

If you have had the parents for quite some time and no birth defects have been prevalent during the course of their mating, the likelihood of such defects is greatly diminished. The Regal Swan