Red - is an appetite stimulant. If your company sells any type of food or snack, it would be a good idea to incorporate red somewhere in your marketing.  Red also increases excitement, since it symbolizes fire. This also makes it a very visible color. That’s why they use it for stop signs and stop lights. Use red in your advertising to draw attention to certain aspects of the graphic design, like the word FREE.

White – Is associated with peace, purity, innocence and contentment.  It is a clean and cool color that can be a classy color and invoke a calming influence. White can be good to use if your industry deals in relaxation - such as a spa or salon, or anytime you want to calm your customer down.  People become more receptive when they are at peace and relaxed.  It also can be use to add uncluttered space to your graphic design.

Black – is a power color, and symbolizes strength, confidence, and authority.  Black is a bold yet sophisticated color and when not overdone is great for creating drama.  If you have a product that needs to have a tough image, it would be a good idea to incorporate black into your design.  Black also can be utilized if your product is very luxury based, as it is associated with exclusivity.  A good example of this would be a jewelry store.  That’s why diamonds always look better on a black background.  But be careful because a black background can hurt the readability of your graphic design

 

Gray / Silver – Is a conservative color and represents high tech.  It is also associated with authority, practicality, earnestness and creativity.  It is a great color to use if your company is in the tech industry as it lends to the authority and technological advancement of your product or service.  Being that gray is a very business wise, creative, and conservative color it can work well for any type of consulting business.

Blue – Is a popular color and great for businesses. It inspires confidence and security. Not only is blue a very popular color but it is also a color that is found all throughout nature. Think sky and ocean and you can see why blue is such a popular color. It is used in the business world to symbolize fiscal responsibility. Although blue doesn't stimulate excitement like red it is great at sharpening focus, so it can be utilized to get a clear message across. Blue can be used great with many different types of businesses.

Yellow – Is associated with happiness, sunshine, vibrancy and fun. Yellow can be utilized in your graphic design to create a state of positive energy.  Yellow is great for use if you are marketing any type of feel good products that involve leisure activities, clubs or social networks.  Another great quality of yellow is its ability to grab attention.  But be careful not to use too much as it can put people on edge.

Green – Green represents health, fertility, renewal, and freshness. It is also a color that is found readily in nature and there it symbolizes growth. Use green in your graphic design to induce a state of calmness and restfulness in your customer.  If your product is all natural and organic, the use of green in your graphic design can really help to get your message across. People are beginning to associate green in advertising with Eco friendly products.

References:
What color is your advertising? How color theory can make your marketing more effective
By Mike Brennan

The Psychological Science of Colors in Advertising and Marketing
By Kurt Geer