Attars oil is good for hairs, its is obtained from herbs. Attars means deep fragrance, scent or essence. These are also obtained spices, flowers or barks, is not the less. No it is not responsible for whitening of beard as well as eye brows. But in a condition when any person use facial creams and on the same day, he use attars essential oil than it reacts and make some hair color change. But most of these oils are used to make light mood, soothe and reduce depression, tension and exhaustion. These oils are also used for pharmaceutical purposes. There are different oils such as herbal attars, Mitti attars or Floral attars which have different therapeutic uses. For making these attars different flower extracts or essentail oils are mixed in defined ratio to develop special quality .Musk attar has an attractive and alluring fragrance; Henna attar has a subtle and sweet fragrance. Lastly, Mitti attar gives a lively and earthly aroma akin to the smell of the rainfall falling upon the dry and hot earth. Yes each type of Indian Attar has a specialty of its own.
Attars are popularly used in India as body perfumes. They have been used for many decades or centuries now. If they induce whitening or discoloration of hair, their popularity would have dwindled over the years. Their continued availability commercially, their high cost and their popularity with certain sections of the society clearly indicate that the answer to your question is negative.