Hi I have my bodykit sprayed, I was worried about differences in colour as well. Especially when I figured out that the guy who was spraying it used a different brand of paint. I gave him the colour code and it worked out fine! There was no difference in colour at all. He used "Sikkens" paint. It also depends on who is spraying it for you ;-) Good luck with it
As a point of reference, I had some alfa rosso touch up paint which I bought for either my Alfsud in 1983 or my Alfetta in 1990. This touch up paint is still OK and is a exact match for my 2001 alfa rosso 147. A competent spraypainter will easily be able to match the colour, IMHO.