What's the worst thing that ever happened to your hair?

Any coloring horror stories? I'll share mine...I have naturally dark hair but I wanted to dye it blonde. Before this, it had been colored auburn (redish brown) but that had faded away. I bought medium blonde dye and covered my hair in it....my hair turned out ORANGE. O.O it was terrible haha but now I'm back to brown and everything is okay, just working on getting my hair healthy :)