Hi I was wondering if anyone had any advice or knowledge on why this has happened, basically a colleague who has highlighted hair level 9 has suddenly turned a tinge of green only very light but noticable, we haven't coloured it for about 6 weeks previously had blonde highlights and the 9/60 illumina toner and was fine obviously its gradually faded out and is more yellowy now but last week suddenly looked greeny? She had used a purple shampoo which looked a bit purple after using so I was thinking maybe it had more blue in it and had faded mixing with the yellow and leaving it green, my other thought was the water and a build up of minerals so we used the wella color renew today to try and get rid of any tone incase it was the shampoo, it helped but is still there. I dont have a photo but it's more of a pale minty green but still looks gold does anyone know anything we could put on to remove or neutralise it? Sorry for the long post! , she also hasn't been swimming or anything like that