Different states of the power system - traffic lights
Green: Power system is in normal secure state.
Yellow: Power system is in endangered state. The adequacy of the electricity is endangered or the power system doesn't fulfill the security standards.
Red: Power system is in disturbed state. Load shedding has happened in order to keep the adequacy and security of the power system or there is a remarkable risk to a wide black out.
Black: An extremely serious disturbance or a wide black out in Finland.
Blue: The network is being restored after an extremely serious disturbance or a wide blackout.