If you are considering hair removal
, then I must inform you that it typically requires pigmented hair as the laser beam targets the pigments and is only then able to kill the hair by destroying the follicles. White hair is not pigmented and is therefore resistant to the effect of laser as it would not absorb the laser beam. The rate of transformation of pigmented hair to white hair is also not possible to predict, and this process cannot be stopped by any means in the present day! The only management you can opt for is electrolysis of the white hair but I must warn you that the rate of removal with this method can be very slow.