I would like to echo Dr. Baolgun's comments. Without melanin (the pigment giving color to hair), then there will be no effect of any laser on the hair. The only method to permanently remove blond/white hairs is electrolysis. Even dyeing the hair will fail to produce an effect with laser hair removal.
The target for the laser in hair reduction is the pigment in the hair. The less pigment in the hair, the less effective the laser is at reducing hair growth. If your hair is gray/white, then the LightSheer or other lasers will not be helpful in reducing hair growth. If your hair is blond with some brown in it, you may find that laser treatments afford you enough reduction that you are satisfied, especially if the hair growth you are concerned about is on your face.