This seems to be a paint finish that is popular with car enthusiasts in the USA.
I found this explanation on the web (see reference). It seems to be a matt paint layer with various layers of varnish (first tinted then clear) over the top.

Regular paint is a solid color and to protect it you put on a clear coat (base coat/clear coat). A candy paint is a solid color base covered with a tinted clear and then protected with a clear coat (no tint).
Regular solid colors are more easily applied. If you put on one coat and it covers it will have the same color and shading as if 3 coats were applied. With candy the more coats or layers of tinted clear you apply the darker the tint will be over the base color. If a silver micro flake is applied on top of your base coat color and then a candy color is applied over that, the silver flakes will change to the color of the candy (tinted clear) color. On my car I shot on a silver base coat first then shot silver microflake mixed with clear, then applied 10-15 coats of red tinted clear and then a few coats of clear. Now the silver microflake reflects red as it is buried under all of the tinted red clear.
Candy paint jobs are a nice finish but if you ever chip it or scratch it don't expect to touch it up as easily as a base coat/clear coat paint job. You will never get the chip fixed right without respraying a whole panel and then you have to hope it matches the rest of the car. If a candy paint is not applied properly it can also have streak marks (light and dark lines in the finish).


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Note added at 11 hrs 51 mins (2004-12-16 09:34:45 GMT)
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The effect here is rather like water colour painting where various layers of thin paint give an impression of depth and transparency. Candy coat(ing) probably more of a process than simply one single layer of paint given the fact that the matt layer is the base with transparent layers on top.