Alert Status
Ship's Status
Federation Starships have been devising means to call for different levels of alertness from their crews depending on a given situation since before the founding of the Federation. The earliest Earth starships used systems similar to that world's navies- "General Quarters" was a state of heightened readiness when the vessel was in danger or in combat. But the system did not ultimately carry over to the Federation.
Instead, Starfleet implemented a system that used the three primary colors in the visible spectrum, those that most Humanoid species would be able to perceive. By far the most common of these are Condition Yellow and Condition Red. Less often used conditions include: Condition Blue, Condition Gray, and "Black Alert."
Implementing an alert status (assuming the computer does not automatically do so) is done from the Operations Manager console on the Main Bridge. The Operations Manager directs crew and resources as defined by the alert status and special instructions from the Commanding Officer.
No Status (Green)
When a ship is under no form of potential or imminent danger, it is at normal operations, has no status, and is sometimes called Condition Green. This is indicated by an inert gray condition icon on most consoles. During normal operations, a starship has power diverted to necessary systems as everyday ship function demands. No systems are prioritized over any other, save at the direction of the Operations Manager.
Condition Yellow
A Commanding Officer, Operations Manager, or the ship's computer can call Condition Yellow. Criteria for Condition Yellow (or Yellow Alert) is that a heightened state of awareness and readiness is called for. The starship is in potential danger and may be operating with reduced resources not at immediately threatening levels. Conditions that call for a Yellow Alert include:
Proximity Alert
A Proximity Alert is when an object large enough to do harm to the starship's hull is detected on a collision or near-collision course by the sensors.
Yellow Alert Reaction
Condition Red
Condition Red or "Red Alert" is the highest awareness and readiness level on the ship. The Commanding Officer and Operations Manager (by way of the Ops console) can call a Red Alert. The criteria for a Red Alert that the ship is in imminent, near-certain and potentially life-threatening peril, be that a combat situation, an environmental disaster, a boarding action, or a widespread power failure.
Brace for Impact
An object or phenomena large enough to do damage to the hull has passed through the navigation deflector sensor band and is on an intercept course. During a "Brace for Impact," crew are to take reasonable measures to secure their positions to minimize injury. A call for Brace for Impact usually is followed by instructions from the Bridge. In Sickbay, a call for Brace for Impact sets Emergency Medical Response Teams into motion: they report to muster stations and Sickbay.
Battlestations
Intruder Alert
Abandon Ship
Self Destruct Sequence
Condition Blue
Condition Blue is found only on some ships in the Federation Starfleet: by those vessels that can land (generally Frigate-sized or smaller) or by vessels that can engage in an emergency saucer separation action. As a Malachowski-class Frigate, the Ulysses is capable of landing. Condition Blue is a form of Condition Yellow- the vessel is in potential peril- but because of the specialized protocols required for landing, it is warranted its own alert status (crash landing is always a Condition Red situation).