Using color codes on messages for the user could greatly reduce the misinterpretation and incorrect responses. Red is a good color to alert the user to an error. Yellow is appropriate for a warning message, and green to show positive progress. Using green for error messages and red for positive status messages will only lead to misinterpretations and frustration for the user. The language of color is important in the use of color.
Individuals develop a language of color as they mature, based on common and cultural usage.
Due to this fact, existing symbolism and cultural use of color should be considered when designing an interface. For example, the postal service in the USA uses blue for postal drop boxes, Britain uses bright red, and Greece uses bright yellow. A legend showing the colors and how they are used should be included for the interface. Color coding on-line documentation for the interface will reinforce concepts the designer wants the user to develop. In addition, color coordination enhances conceptualization through clustering and bringing elements to the user' s attention by association with existing mental models.