Alert signal

Signal status display on the USS Excelsior.
From top to bottom: "red alert", "yellow alert", "normal", "stand by", "auxiliary".

Aboard Starfleet starships and outposts, a series of color coded, and also generally named, alert signals are issued, usually by the ship's computer or internal communications systems.

• red alert (condition red): Critical situation:
  • general quarters
  • battlestations
  • double red alert
• yellow alert (condition yellow): Elevated alert.
• green alert (condition green): Normal status.
• blue alert (condition blue): Environmental, docking/separation or landing alert
• intruder alert
• tactical alert
• collision alert
• decompression alert
• battle alert
• Reduced Power Mode
• Grey mode
• security alert
• standby alert