there are so many different kinds of plantains. not sure if you always get the same or what. i've had ones that will turn colors, and ones that will just stay green til they rot.
the green ones are pretty much impossible to peel if they're unripe [not sweet, more like a potato]. you have to cut off the skin, you can't peel it like a banana.
this sounds like exactly what happened.
we pretty much have to buy whatever plantains they have at the store that day so maybe it was a different variety than normal.
i had to slice the peel off some parts because i was having such a hard time peeling them and after my fingers and nails were left with black all other them that actually looked like ashes or soot.