B744 Oil Quantity
 

Qantity differential
 

Don't know about -400, but it sounds like a differential between engine oil quantities for individual engines.

Your answer in Magenta has "popped-up" from the -400 manual below;

Difference Quantity

Oil Quantity Difference Monitoring begins when;

•At least 2 Engines are running within 2% N1 RPM, and
•The change in altitude of the Airplane is less than 200 feet/min or the aircraft is on the ground motionless.
An automatic pop-up of all oil parameters occurs when the difference in oil quantity between the high and low quantity Engine is 7 Litres
for greater than 180 seconds;
•The indication, which represents the low quantity Engine, will turn magenta in colour at the differential limit.

:ok:
.

Great stuff Spanner Turner!
Thank you...
Durango:ok:

"During cruise, oil quantity displays on EICAS whenever oil quantity on one
engine differs from any other engine by a predetermined amount. When this
occurs, the lowest oil quantity is shown in magenta. If there is an increase in oil
quantity during cruise (indicator malfunction or leaking fuel/oil heat exchanger),
the EICAS oil partial engine indications display may appear. However, for this
condition the low quantity displays in magenta, even though that oil quantity may
be normal."

I thought the quantity difference was 5 quarts, but they have removed the number from the FHB. Perhaps a customer specific option?