I am of the opinion that when it comes to advertising / marketing / branding, the Americans are the most reliable source of information. These functions / processes are part of their culture – the art of selling is part of the platform they have based the “American Dream” on (whether this is right or wrong that is a different discussion all together for a different forum).
I believe that the way colours affect our perception over products is a global phenomenon to a great extend. Most probably there are differences from country to county but they cannot be major.
Us - South Africans – can only benefit by noticing these business “basics” or “trends” in whatever we do – since we chose to operate on the most volatile platform one can choose to make his living from: self employment.