Paint troubles

I've recently just started on the bodywork of my Fabia vRS, stripped the bumpers back etc. Just got round to painting and the paint code in the boot is 9102, diamond silver, although on having some paint mixed it has come out a shade darker, I'm sure if this because I used a grey primer and it's only the first coat and it'll get lighter or if the 9102 paint code has run through into variou years and I picked the wrong one but a man from Skoda parts told me otherwise. Any help would be handy and if it isn't the right paint, any ideas where I could the right one in something bigger than a 150ml touch up bottle would be fab too.
Thanks
Jacob