Some heads are making staff use up to six different coloured pens to give different types of feedback

Teachers have complained about a ‘ridiculous’ marking system which forces them to use pink ink for negative comments because it is ‘less aggressive’ than red.

The bizarre system is being implemented by some headteachers who believe pink is a softer colour which will make children feel less like failures.

Many are also making staff use up to six different coloured pens to give different types of feedback to pupils as part of a ‘triple’ or ‘deep’ marking strategy.

Teachers have complained about a ‘ridiculous’ marking system which forces them to use pink ink for negative comments because it is ‘less aggressive’ than red

In one example, a school has asked pupils to respond to teachers’ comments in purple or blue, and if teachers want to give encouragement they have been told to use a ‘positive’ green pen.

It is thought the system was inspired by Marking Matters, a guide from Ofsted, the schools regulator, issued in 2011 but withdrawn last year.

At the conference of the NASUWT teaching union in Birmingham at the weekend, teachers voted to escalate industrial action over the pressures of the marking system.

Chris Keates, the general secretary of the NASUWT, said: ‘Too many schools are continuing to impose marking regimes which pupils and teachers find debilitating.

‘Teachers are being subjected to policies which dictate when to mark, how to mark and even the colours of the pens to be used.’

Michael Parsons, who teaches at Roath Park Primary School in Cardiff, said his school uses a system of pink and green pens for marking.

He said: ‘It’s green for growth and pink for progress. To be honest it’s lost on me . . . and I know it’s lost on the children.’

According to a recent survey, primary school teachers on average spend 10 hours a week on marking

Lee Williscroft-Ferris, a modern languages teacher from Durham, said that in one school he worked at he had to draw a pink box at the end of each piece and insert positive comments in green ink and suggestions for improvement in pink.

According to a recent survey, primary teachers on average spend 10 hours a week on marking.

The government this weekend accepted recommendations made in an independent report to encourage teachers to give more verbal feedback in lessons.

Teachers have long complained that the complicated marking systems create unnecessary extra work and detract from actual teaching.

It is understood heads have adopted them so that they have written evidence of rigorous feedback to show to Ofsted inspectors.

But education secretary Nicky Morgan is against the practise and is working on strategies to reduce teacher workload.