No, this particular coloration is known as leucistic. All Mute swans are Mutes. However, there are two colors coined by swan keepers. The Royal Mute is the normal coloration in which the adults have reddish orange beaks and black feet/legs. Their young are taupe/grey in color.

The Polish Mute is the leucistic form in which the young are white in color and buff colored feet. The adults have orange beaks and buff colored feet/legs.

If the parents appear to be Royal Mutes, it only means that along the gene/DNA line, the leucistic coloration was present and is now showing itself. This leucistic coloration may or may not show itself again during the swan's lifetime breeding cycle. The Regal Swan