Would depend on the following factors: respiratory rate, perfusion to skin, mental status.
Typically, an amputation with significant bleed would hit the respiratory rate (>=30/min) and perfusion (cap refill >=2 secs) thresholds for 'Red'.
That said, I've been present at a plane crash with four patients where one had a clean amputation that had had a tourniquet applied immediately following the crash. He was speaking clearly, had adequate perfusion, and was breathing appropriately. Technically, this patient could be categorized as a 'Yellow' and was, in this case, considered a lower priority than the head injured patient trapped within the aircraft.
During a multi-casualty incident (MCI) the commonly used START triage system would invariably categorize a patient in cardiac arrest as 'Black' or 'Expectant'--these patients are typically passed over so that medics can treat more viable patients.
Additionally, pulses aren't used for determining whether a patient is 'Black'. Instead, medics will check to see if the patient has spontaneous breathing: if respirations are absent, the airway is positioned (typically jaw thrust or head-tilt chin-lift). If no spontaneous breathing is present despite positioning, the patient is assessed as 'Black' and the triaging medic moves on.
It is grim, but at a true trauma MCI (# patients >>> # rescuers) there should be no healthcare practitioners or rescue personnel performing CPR. This seems harsh but given the low odds of survival to discharge of traumatic cardiac arrests, it makes perfect sense in an MCI scenario.[0]
[0] Work as a Critical Care Paramedic, to lazy for real references :P
Typically, an amputation with significant bleed would hit the respiratory rate (>=30/min) and perfusion (cap refill >=2 secs) thresholds for 'Red'.
That said, I've been present at a plane crash with four patients where one had a clean amputation that had had a tourniquet applied immediately following the crash. He was speaking clearly, had adequate perfusion, and was breathing appropriately. Technically, this patient could be categorized as a 'Yellow' and was, in this case, considered a lower priority than the head injured patient trapped within the aircraft.