In a school security lockdown, teachers typically display red or green cards on the doors or in the windows of their classrooms. The manual procedure uses red cards to alert to a crisis condition; green cards designate that everything is safe inside the classroom or office.
Colour-coded crisis management system
Physical security company Sielox has adapted the idea of using a colour scheme to characterise an emergency situation into its electronic security system. CLASS [Crisis Lockdown Alert Status System] by Sielox is an incident and crisis management solution that uses a variety of colours to designate the emergency conditions in various parts of a school building – red to alert to a crisis condition and green to designate "safe/secure." Colours are displayed on a schematic of the building, and new colours have been added,...