Turns out the carpet was 50:50 wool:silk.
Prochem Solvex and Chemspec Textile Rinse sorted it.
Unfortunately they had already tried one of them with Vax spotter and had removed some of the colour.
Nothing major and only noticeable if you knew it was there. at the rate this carpet has faded (6 months old) it shouldnt be long before it will blend.
Thanks for the input everyone.