Best off just buying paint at the site, as it already been said that you would have to match the shell and fil with whats on offer at the site that day.
Delta Force marshall's do keep an eye out for this sort of thing going on, as for every punter we catch using their own paint we recieve a fiver bonous.
Saying that though as long as the paint is sound paint (e.g. not frozen or gone rubbery) If i found you using it i would strongly urge you to put it in your car and buy site paint for the rest of the day, rather than throw you out. but if you continued to use your own then we would be forced to ask you to leave the premises.
My point is if you do take your own and get found out, if the site allow you to stay see this as them being nice show em some respect and purchase some site paint
, but my advise is to not bother as you will get found.