Kirsty Wark has unveiled a 'shocking' new hair style on Newsnight after choosing to go grey for a day.

Ms Wark ditched her brunette locks in favour of the new bob for a segment on the BBC show about scientists pinpointing the gene that causes grey hair.

The discovery could lead to new ways of delaying or preventing grey hair.

The Scots presenter, who wore a grey wig during Newsnight, received a positive reaction on Twitter for her new look.

The Scots presenter looked at society's view of grey hair and why people are often choose to hide it during her piece.

Alex Brownsell, founder of Bleach Hair Salon, told Ms Wark: "It's the double standard that there is with all ageing. Men become more attractive and more intelligent as they get older. There's the silver fox but there's no silver vixen. Maybe following this trend will start that."

However, fashion expert Caryn Franklin, who has been grey since her thirties, told Ms Wark that she loves her distinctive hair colour.

She said: "My oldest daughter says 'I better get a white streak or else' and 'I hope I've got your gene package Mum' because she's seen it and knows that it's distinctive."