Hello Carl,
The pantone colour used in printing the grey was 7544C, if that's what you mean. I can't give you an exact match from standard paint ranges, I'm afraid. I suggest that you try mixing a grey starting from something like RAF Medium Sea Grey adding or lightening as required. Alternatively small pieces cut from the spare grey decals provided might be more use than painting?
Hope that is some help. Nice to hear of these decals being used - they sold out very quickly and perhaps a reprint might be in order.