I still think we can do it with out a lot of circuitry. If the Refill terminal has no voltage until the yellow LED is turned on and the warning terminal has 12V when you want the orange LED operate on both conditions(flashing/not flashing) it can be done two ways one with a 555 timer and an additional transistor(NPN). The other way is with a flashing LED and two transistors(1 NPN and 1 PNP). Both circuits would require a few extra parts but no additional IC's
I am going out of town for 2 days so I'll check when I get back.
As a side note: If the Power,Operation,Warning and Refill terminals have either no voltage or +12V with respect to ground the diodes connected to each LED is not necessary.