I did have dyed blonde hair and went to a salon to have some darker bits put through to break up the blonde. It went khaki green, dull and greyish.
The salon refunded me so I went to a new salon which put a pre-lightener on and full head highlights. The hair that was left out of the foils is still green and can be seen between the highlights which turned out great.
What can I do to hide this green? It is making my life miserable!
This is colour correction work and you need to go see someone who understands the process of gentle cleansing and deep cleansing of hair. The greenish hue is created when a flat colour with no warmth is applied to prelightened hair, this is down to inexperience with complicated colour work. The hair grabs onto the colour pulling in the shade too deeply because it is porous from being bleached.
Remember to tell the colourist your hair history and maybe go armed with some ideas of what you want to achieve. Once the colour has been fixed remember to condition it well and keep it moisturised.
John Clark at Brooks+Brooks, London