WINCHESTER, England, Nov. 13 (UPI) -- A Winchester, England, couple said their daughter was suspended from school for dying her hair months after her sister did the same thing without consequences.

Stuart and Dawn Gander said their daughter, Kirby Moore, 13, was suspended from the Kings' School after she changed her hair color from light to dark brown, The Daily Mail reported Thursday.

The couple said their 15-year-old daughter had changed her hair color months earlier to a lighter shade of brown than her natural hue and no teachers had complained.

"Our uniform code is clear. Hair must be in an appropriate style and must not reflect any extreme of fashion," King's School Headmistress Sue Lawrence said in a statement.

However, Dawn Gander said her daughter's "hair looks perfectly respectable."

The couple said they are keeping both daughters at home after school officials told them Kirby would have to remain in isolation from her classmates until her hair is back to its natural color.

"We agree pupils must abide by the school's rules," Stuart Gander said. "But we cannot accept one rule for one daughter and another rule for the other."