I got them to match a patch of leather I sent them but they didn't do a very good job, so I sent it back, the final mix still has too much yellow in the mix but I can live with it.
The seats came out of a MK1 TT, I decided to swap the seats as the original ones are not very comfortable and very expensive to refurbish, so they have gone into storage. The TT seats are not a perfect colour match but they are close enough for me. No need to dye them.