Candy colour is in fact a combination of a base coat and over is a see through (ink) layer.
The colour is determined by how much concentrate you add to the clear. As has been explained before in this topic.
There is no way to take an existing tank and get a code on candy, sorry.
So, I spray candy on Honda tanks for a living. (I'm sorry I'm in Germany, Europe)
These colours are simply not easy to replicate let alone spraypaint without any flaws.
I don't use paint kits, I mix the colours myself.
What might be interesting to know: the colours leaving the factory would have had differences as well on a day to day basis.
Same paint but different painter would already be enough to have a slight difference in colour.
So the painter on monday would do 2 thick layers with a wide beam and the next guy would spray a bit more careful and do three layers with a wide beam but with 5 centimeters further away from the tank. Colour looks about the same but mondays tank would not be the same as the tuesday tank. And that explains why a single aftermarket panel is always different and also why a complete set is worth so much more.
here some nice colours:
http://www.tanklackieren.de/Honda-colours/