One of my favorite current Cadillac colors is Thunder Gray ChromaFlair. Cadillac has a summary ChromaFlair site here.
ChromaFlair is a paint process in which metallic flakes in the paint act as tiny prisms, and reflect light differently in different lighting conditions. In other words, the car color changes somewhat when seen in different lighting, or sometimes at different angles. The ChromaFlair colors are premium paints for Cadillac, and tend to bring an additional $995 charge for new vehicles.
Unfortunately there is not a great way to show the color online.
Here is what JDSU, the manufacturer of this process, says about it:
ChromaFlair pigments are unique, multi-layer pigment flakes that give paints, coatings, plastics, textiles and packaging the ability to change color when viewed from different angles. Created using a revolutionary thin-film technology, each flake exhibits a wide range of hues depending on the angle at which it is viewed and the angle of incidence of light – a dramatic color shift that is even achievable in low-light environments. Highly chromatic, durable and easy to incorporate, ChromaFlair pigments can add value and appeal to virtually any product where color is a key differentiating factor.
Thunder Gray ChromaFlair is a medium gray metallic that can appear to have a blue or green tint in different lighting conditions. In any case it is a conservative, elegant color. But deeper and more complex than a simple gray. It is a subtle, refined mix of colors that suit the Cadillac line well. The shift is subtle, but Cadillac Owners do report having difficulty finding their car on occasion, or not recognizing their car as they approach it due to the color shift.
ChromaFlair is a registered trademark of JDS Uniphase Corporation.