Working with color schemes, can say that the most selling files have a specific color combination or scheme.
Still the black only or profile has a great acceptance and grab a lot of attention because its usability and can combine in any light background.
Lavender generates great attraction and is the most used plain or in gradients.
Vivid green is also very used in all web 2.0 and in combination with lavender.
Red and gold or black and gold are elegant combinations and very downloadable