"He always did himself well, Lucius. Peacocks . . . ”
-- Yaxley (DH1)
Albino peacocks, also known as White peacocks, are large birds with expansive tail feathers. They are similar in size and behavior to the more familiar Indian Blue peacocks.
Real albino animals have pink or red eyes, but in peacocks the white color is caused by a different genetic mutation known as "leucism," so their eyes remain dark. To keep the colors pure they must be raised in captivity - or on a country estate, in the case of Malfoy Manor. Maybe the Malfoy family used a little magic as well. source: Wikipedia