[Mike Halliday]

Peter M raises a very important piont....are you sure they were P/P?

to be honest i never do a fibre check on commercial carpeting and just assume they are a man-made fibre, if you have done the same then this opens other options, If they were a nylon tile then you can lose colour or be more susceptible to pre-existing stain removal attempts.

[Doug Holloway]

Hi Guys

Roger is right, decaffinated coffee contains artificial colouring and is harder to remove than natural coffee.

I would try oxidising and reducing on seperate areas and see how I got on but sometimes they are permanent.

Tiles were probably nylon or a mixture.

Cheers

Doug