HK is correct about the kandies...but here is how I explain candies to my customers when I'm trying to pimp a bit more out of a respray.
Imagine that there are only 2 types of paint jobs, 2-stage (bi-stage/bi-coat) and 3-stage (tri-stage/tri-coat). (there are many other ways to paint a vehicle, but these are the most popular with todays most popular paint: Urethane)
A two-stage paint is one that has two parts (duh!)...a Basecoat (the color that the vehicle is; Black, Yellow, Flame Red, Grandma's panties Green...whatever), then a clearcoat (many layers of Clear sprayed...together called The Clear Coat) over that.
The Basecoat, if sprayed by itself looks very dull...it's basically just a layer of color. The basecoat can have additives in it, like pearl, metallic, and color-change prisms. But it's still relatively dull when sprayed.
The Clearcoat is what makes the surface shiny. It's just there to act as a flat, polishable surface that protects the color layer from the wind, rock chips, UV rays, bird poop...whatever. That's all that it does.
That's your basic 2-stage paintjob...spray it a color, then clear it.
Your 3-stage paintjob has another step BETWEEN the normal steps. Lets say you spray your car bright-*** Viper Silver. It's a very VERY sparkly, metallic silver. Then, lets say that you dillute a color (say, a dark red with lots of pearl added) with clearcoat, say 50% paint and 50% clearcoat. You're going to have a Semi-transparent Red Pearl, right? If you spray that Red-pearl over the silver base, you are going to be able to see the silver sparkle THROUGH the Red-Pearl coat. This makes the red look lighter, Sparkly, and DEEEEEP! The more coats of Red you put on, the darker the Red looks, and the less you can see the silver. This is, Basically, Kandy-Apple-Red. You get Kandy-Cobalt-Blue by shooting a Cobalt-Blue Kandy Coat (a semi-transparent Blue-Pearl) over another color (say, silver, or Gold). Kandy-Tangerine is Semi-Transparent Tangerine over another color.
Then you put clear over the whole thing, just like before.
The reason that tri-coats are harder to spray than 2-coats is that imagine when you spray a 5"wide stripe of pearl over the silver across your panel. Then, imagine coming back and trying to spray your next stripe RIGHT NEXT to the first one, without any overlap...because where you sprayed would be 1-layer thick. If the two stripes overlapped, the red would be 2-layers thick, and would be darker, right? *This isn't how you spray a kandy...you actually do overlap, but I'm not going to get into that here*. Plus, if you put a run in the kandy-coat...there's nearly no way to fix it without re-spraying the base color and re-kandy-ing the entire peice. Kandy's are the BEST colors in MY opinion...but they are difficult to shoot, and difficult to fix if you have a wreck down the road sometime.
Hope that helped.
The 'hopper