Red Alert: Alert being declared at times of great danger, especially to the imminence of a natural disaster, for example a flood, tornado, etc.
A red alert is the highest level of threat or warning in various information systems and it is often used to indicate a particular type of emergency. This type of alert literally means red lighting used to indicate danger.One of the reasons by which is used red is because the human eye adapts more easily to darkness from the red with another color. Why use becomes an advantage when in certain situation all other lights are turning, because of the emergency.