Interesting article, though as others have said, I'm not wholly sure that there was ever an intention to applaud "whiteness" as such in Roman statuary. (After all, Roman black marble and bronze were quite happily accepted by later aesthetes, weren't they?)
Rather, I suspect it was the *simplicity* of a monochromatic statue that appealed to 18th century tastes.
In a rather similar way, the copious use of bright colours on the exterior of buildings in medieval Britain, and for wall paintings inside churches, was generally ignored by the Victorians. They *wanted* the middle ages to look plain and sombre, in the way they wanted the Romans to look dignified and unflashy.
The fact that a favoured Roman material happened to be white (which of course is nothing like the colour of "white" skins anyway) was coincidental.