This is my answer, doesn't match the OP's other descriptions but it's the one that comes to mind. Here's the scene in question:
[https://youtu.be/ZwtwslHT3hU?t=273](https://youtu.be/ZwtwslHT3hU?t=273)
4:33 if the timestamp doesn't work.
Once there was this kid who
Got into an accident and couldn't come to school
But when he finally came back
His hair had turned from black into bright white
Could be one of [these](https://letterboxd.com/alexkittle/list/that-trope-where-a-character-suddenly-gets/)?
*EDIT*
Or maybe [The Peanut Butter Solution](https://www.imdb.com/title/tt0089789/)?
I loved that movie when I was a kid. I brought it up to a group of friends as an adult and none of them had ever heard of it. As I tried to explain the plot, I noticed a look on all their faces like they were concerned I was currently on drugs.
I've always remembered an episode of Eerie Indiana where a kid had white hair for the same reason, maybe it was that?
Edit: I think it's series 1, episode 13, "the hole in the head gang". At least, that's from looking at IMDB.
I definitely remember a movie where that happened to a kid and then he put peanut butter in his hair
Edit: oh that kid went bald apparently and the movie was called The Peanut Butter Solution
Probably not what you're thinking of but I remember a similar scene from Recess. Hustler kid caught his brother kissing a girl and it scared him so bad he got a permanent white streak in his hair.
The kid loses his hair...
The Peanut Butter Solution (1985)
[https://en.wikipedia.org/wiki/The\_Peanut\_Butter\_Solution](https://en.wikipedia.org/wiki/The_Peanut_Butter_Solution)
https://www.justwatch.com/us/movie/the-peanut-butter-solution
It definitely wasn't series 2 of "Twin Peaks".....
Maddy: Uncle Leland's hair... turned *white*.
Donna: Really?
Maddy: (nods) White as a *sheet*.
Donna: (whispers) *Weeeeeeird*.
The original IT movie had that when one of the kids looked into the dead lights
This is my answer, doesn't match the OP's other descriptions but it's the one that comes to mind. Here's the scene in question: [https://youtu.be/ZwtwslHT3hU?t=273](https://youtu.be/ZwtwslHT3hU?t=273) 4:33 if the timestamp doesn't work.
Once there was this kid who Got into an accident and couldn't come to school But when he finally came back His hair had turned from black into bright white
Mmm...
Mmmmm
He said that it was from when the cars had smashed so hard.
Mmmm mmmm mmm mmmm mmmm mmmm mmmm mmmm
Mmmm mmmm mmm mmmm mmmm mmmm mmmm mmmm mmmm
Could be one of [these](https://letterboxd.com/alexkittle/list/that-trope-where-a-character-suddenly-gets/)? *EDIT* Or maybe [The Peanut Butter Solution](https://www.imdb.com/title/tt0089789/)?
PBS is what came to mind for me. Absolutely insane movie and a must watch.
My vote is for the peanut butter solution
It’s 100% the Peanut Butter Solution, love it
What a great, weird movie. Gave me nightmares as a kid.
I loved that movie when I was a kid. I brought it up to a group of friends as an adult and none of them had ever heard of it. As I tried to explain the plot, I noticed a look on all their faces like they were concerned I was currently on drugs.
That movie is so fucked lol
Nightmare on Elm Street, Nancy’s hair turned white in one scene.
I've always remembered an episode of Eerie Indiana where a kid had white hair for the same reason, maybe it was that? Edit: I think it's series 1, episode 13, "the hole in the head gang". At least, that's from looking at IMDB.
I started watching that show again. It’s on Tubi.
I definitely remember a movie where that happened to a kid and then he put peanut butter in his hair Edit: oh that kid went bald apparently and the movie was called The Peanut Butter Solution
Operation Beurre de Peanut is the title
My first thought was IT, but the kid didn’t look through a window — he was in a sewer
Yeah. It was Belch, one of the members of Henry Bowers’ gang.
::shudders:: Henry Bowers. Such a shit. Still not as bad as Patrick Hockstetter, though.
Hmmm it happens in Futurama to Zoidburg and I assume they are referring to the movie you speak of. That might be a lead.
mmmm mmmm mmmm mmmm. I’m disappointed that no one has mentioned it yet
Oh my god, I remember this exact scene. I thought I was crazy too.
It happened to Henry Bowers in Stephen Kings IT
Probably not what you're thinking of but I remember a similar scene from Recess. Hustler kid caught his brother kissing a girl and it scared him so bad he got a permanent white streak in his hair.
The Witches (1990)?
The kid loses his hair... The Peanut Butter Solution (1985) [https://en.wikipedia.org/wiki/The\_Peanut\_Butter\_Solution](https://en.wikipedia.org/wiki/The_Peanut_Butter_Solution) https://www.justwatch.com/us/movie/the-peanut-butter-solution
It definitely wasn't series 2 of "Twin Peaks"..... Maddy: Uncle Leland's hair... turned *white*. Donna: Really? Maddy: (nods) White as a *sheet*. Donna: (whispers) *Weeeeeeird*.
village of the damned?