All mute swans are known as Cygnus olor in Latin species taxonomy. Although there is no scientific differentiation for a "royal or a polish" mute, swan keepers normally refer to the coloring as such.

Centuries ago, someone in Poland or Hungary tried to establish a colorless swan or an albino. They kept inbreeding the same swans and the cygnets until the coloring was washed out for the albino status. This never happened but what was produced was a leucistic variation that at one time was deemed a new species known as the colorless swan. However, it was later established that this was not a new species only a leucistic or genetic anomaly that produced the "polish" mutes.

"Royal" mute cygnets are taupe in color with black legs and feet. The adults will have a reddish/orange beak.

Leucistic "Polish" mute cygnets are white in color with taupe colored legs and feet. The adults will have an orange beak.

There is nothing wrong with the cygnet and it may actually produce "royal" cygnets during its breeding life. The Regal Swan