The color gun sucks...I've tried to use DuPont's, it doesn't work at all, PPG's is just as good...it doesn't work at all either, especially metallic colors. If you have a paint code and your not sure if it's correct, have the paint store mix up a small amount, if it's right they can just add it to what your buying. For example if a quart is 1,000 grams, have them mix 100 grams, if the color is right have them mix another 900 grams and you have your quart, or pint or what ever size container you want. If the color is wrong, then you can try the code that the color camera magically came up with. Hold your breath and keep your fingers crossed, say 5 hail Marry's, 3 Our Fathers and buy a rabbit's foot before you go with the formula that the camera spits out. My experience is that the camera will give a blendable match between 5% and 10% of the time.
Oh did I mention, I don't trust the camera!