Is there any type of physical way this can happen scientifically or is it just BS? Could someone in a moment of near trauma, lose their hair color? How about something with electricity - someone once told me that a few people who have been struck by lightning have streaks of white where the bolt hit.
Well, it’s certainly possible for a traumatic experience to cause someone’s hair to start coming in white, but since everything above the root is dead tissue I don’t see how somebodys existing hair could turn white, especially overnight as it is commonly portrayed.
The only way your hair turns white, short of bleach, is for the pigment-bearing hair to die and fall out. Everyone has some white hairs. Most of the time, except in the aging, they are outnumbered by colored hairs, so your hair looks uniformly black or brown or blond. Something like an electric shock would kill cells in the area pretty much indiscriminately, which might have the net effect of burning off colored hairs and leaving a few white hairs behind. Pure chance there, it could just have easily left a few colored hairs behind. I don’t think stress can do it, unless stress causes you to physically rip hair from your scalp. Of course, I will be corrected if I’m wrong, so keep an eye on this thread.
Here’s the Master’s take on this subject: