About.com defines corporate house style as a set of guidelines used in companies and organizations of all types that governs punctuation, spelling, capitalization and other matters related to the readability and visual appearance of printed documents and web sites. A corporate style may follow an established style such as Chicago or AP, or it may be a style unique to the corporation.
Corporate house style is an essential component of branding a company in the minds of potential customers. Key elements of house style are color, font and typography, logo and tone of language.
Different colors have unique psychological effects on people. For example, orange is energetic and attention-grabbing, while blue evokes trust and stability. A corporation must pay considerable attention to the colors it uses in its internal and external communications.
Fonts and typography are also important to how a company presents itself. Heavy fonts imply seriousness and trust, scripted fonts elegance and sophistication, while others are cute and playful. It is doubtful that a law or public accounting firm would use the same font and typography as a sports franchise or fast food chain.
The logo is another key element of a firm's house style. It is a visual representation of the company, and the best logos are easily recognizable by the public. McDonald's Golden Arches and Apple's once-bitten apple are two famous examples.
Finally, as with the other elements of corporate house style, tone of language is used to cement the company's place in the marketplace.