A seven-year-old girl's blonde hair turned bright green after she went for a swim at a leisure center in Morrison, near Swansea, England, ananova.com said.
Paige Williams said her hair changed color after a school outing. She said she discovered the change in her hair after removing the orange rubber swimming cap from her head.
Her classmates are teasing her "Hulk's Daughter" after the television character, and her family insisted they have tried everything to get the color out but nothing has worked so far.
The family fears Paige will still have her hair green for Christmas.
Her mother Lucy Williams, aged 24, of Tirpenry, Morriston, said, "She has been going to school with vinegar and, lemons in her hair to try to bleach it out."
A spokesman for the Swansea Council said the girl was wearing her hair in a bobble under her cap which could have been possible for the change of color.
Tests conducted on the chemical levels in the pool had been normal, he said and added, "Staff have been closely monitoring the pool since the matter was noted and no further incidents of this nature have been reported."
