A schoolgirl who dyed her hair auburn has been threatened with 'isolation' if she doesn't return to a natural colour.
Olivia Senter, 14, has already received detention for her 'unnatural' hair and has now been told she will have to work alone if she keeps her colourful barnet.
Poltair School in Cornwall said Olivia's hair colour was breaking school rules and her grandmother Anne Mounce said Olivia felt she was left with no other option but to agree with the school's ruling.
However, she branded the school 'heavy-handed' and 'extreme'.
She said the school's policy on hair colour states that only unnatural colours such as purple, blue, green, pink, or those which attract 'undue attention', are unacceptable - but insisted that Olivia's auburn shade was nothing of the sort.
Mrs Mounce, from Penwithick, told her local paper: "I have looked at the school's policy and it says in black and white non-natural colours are not allowed and then lists blue, pink, green and purple.
"Her hair is none of these, it might be slightly redder in some lights but red is not even on the list as not acceptable."
Olivia dyed her hair at Easter but no concern was raised until a fortnight ago. Her grandmother said Olivia was spoken to and then told by the school's head of house that if it wasn't dyed back by Friday she would be sent home.
"It is taking the rules to the extreme. Olivia usually looks forward to school but she told me the last few weeks have been terrible.," said Mrs Mounce.
"We have one of three choices; she dyes it back, or she doesn't and goes into isolation, or I move her to another school which she doesn't want because all her friends are here and she is doing so well.
"It's emotional blackmail."
In a statement, head teacher Stephen Tong said the current policy is two years old and had been written following full consultation with the Student Council.
"The pupils of Poltair School set exceptionally high standards in all that they do," he said.
"This is reflected in their school uniform. It is worn with considerable pride.
"The current policy, devised two years ago, is explicit in terms of the expectations of pupils. The school upholds and enforces the policy."
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