What color standards should be followed in HMI design?

HMI color standards (ISA-101, EEMUA 201): use gray background for fatigue reduction, limit color palette to 4-7 colors, reserve specific colors for specific meanings (red = alarm/danger, yellow = caution/abnormal, green = safe/running - but note contradicting industry conventions). Avoid using color as only indicator (color blindness consideration). Equipment should be gray when normal, colored only when abnormal. Text should have high contrast. Animations should be subtle. Test with actual operators under actual lighting conditions. Document color coding in project standards.