Yellow certainly plays a part in Dark Glamor. Gold is yellow, as are certain alcoholic beverages. Working the decadence angle, I feel the use of the color was very successful in the branding strategy for Paris Hilton's canned champagne, RICH. Aside from the fact that canned champagne in over-the-top glitzy packaging is extremely campy, I think it gets the message across.
Decadence and extravagance are the desired appeal here. There is no subtlety; it simply screams at you. Not to muddle the effect, no competing colors are used-- the scheme is absolute and straightforward. The sex appeal and decadence of the color are translated throughout the marketing campaign. From the nude celebrity, to the appeal of the product, to the coveted precious metal, yellow is the element which synthesizes all the implied themes.
If promoting a product titled "RICH," would there be a more natural choice than a hue indicative of a precious commodity? Yellow gold having a classic standing as a herald for wealth is a fool-proof choice. Tacky and obvious as it may be, the choice here was completely successful.
Other examples of using yellow to communicate wealth, privilege and decadence.