For example John Deere has trademarked the distinct shade of Green for their farm equipment line and Coke has trademarked the distinct shade of Red for its cola products. These colors are a crucial branding or product identifier for these companies and companies trademark the distinct color or color combinations to identify their products in the market place.
First, to qualify as a trademark, the color scheme can have no functional purpose.
Second, Applicant would have to show that the consuming public recognizes the color scheme as a source-identifier, i.e., that it has achieved secondary meaning.
If yes that you may be able to pursue color as a brand identifier.
By Mat Grell, US Trademark Attorney