Signal status display on the USS Excelsior; from top to bottom: "red alert", "yellow alert", "normal", "stand by", "auxiliary"
Aboard Starfleet vessels and outposts, a series of color-coded alert signals were issued, usually by the ship's computer or internal communications systems.
The Earth Starfleet began without an alert status system (signal) until one was suggested by Lieutenant Malcolm Reed aboard the prototype Enterprise, an early starship that had a larger crew and a greater need for reaction time during crisis situations.
Colored alerts[]
- Red alert (condition red) – critical situation, denoted by flashing red warning lights and audio alarms.
- Yellow alert (condition yellow) – elevated alert
- Blue alert (condition blue) – environmental, docking/separation, or landing alert
- Gray mode
- Black alert
- Green alert
General alerts[]
A Galaxy-class alert indicator in normal, yellow alert, and red alert modes
- Abandon Ship Klaxon
- Alert status four
- Battle alert
- Battle stations
- "Brace for impact"
- Emergency stations
- Evacuation alert
- Fire alert
- General quarters
- Intruder alert
- Perimeter alert
- Proximity alert
- Security alert
- Standby alert
- Tactical alert
| Alert signals | |
|---|---|
| Colored alerts: | Red • Double Red • Yellow • Blue • Gray • Black • Green |
| General alerts: | Battle stations • "Brace for impact" • Emergency stations • General quarters |
| Battle • Evacuation • Fire • Intruder • Perimeter • Proximity • Security • Standby • Tactical • Visitor | |