Metallic and pearl colors are available in single-stage, 2-stage & 3-stage paint process technologies but they are not created equal.
The process and materials used in 2-stage paints result in a more uniform layer of color that causes the flakes to lie more flat, reflect more light and create beautiful finishes. The single-stage process is not capable of achieving the same results and certain colors--especially golds, silvers, champagnes and bronzes--can look dull and grey in single-stage when compared to 2-stage and 3-stage paints. When color is important, choose 2-stage paint to achieve the right hue & brilliance.
For certain colors and special effects in finishes like "candies" and pearls--especially pearl white--it may be necessary to go another step into 3-stage paint to achieve the desired result. The Nissan Altima in the photo has a 3-stage pearl white paint job that gives the white a luminosity and brilliance that single- and two-stage paints cannot come close to.