I have mentioned this fundamental HF design need in several of my postings. CONSISTENCY is key in helping reduce human error. I like to use STOP signs as my example. But here are some fundamental principles when analyzing computer screens, workplace signs, etc., when it comes to COLORS…
The number of colors used to code information should be kept to a minimum, NOT TO EXCEED four (4) colors for casual users and seven (7) colors for experienced, long-term users.
Do NOT violate POPULATION EXPECTATIONS regarding use of color. Several examples of population stereotypes are:
- Red: indicates Stop, Warning, System Operating Out of Tolerance
- Yellow: indicates Caution
- Green: indicates Go Ahead, System Operating Within Tolerance
Color codes should be applied consistently throughout the system; colors should have the same meaning the system can display.
As the number of colors used increases, the size of color-coded objects should be increased.
Use compatible color combinations when colors are presented simultaneously.
- Avoid red/green, blue/yellow, green/blue, and red/blue pairs unless an attempt is being made to make different parts of the screen/sign appear in different planes.
Source: Federal Highway Administration Research and Technology