Rat Out
The Ram Air Turbine (RAT) powers the Blue System, not the Yellow or Green. The RAT will automatically deploy when you have a dual AC electrical failure..... You can manually deploy the RAT, but only powers the Blue system and its associated systems. Because of redundancy, the blue system touches most systems and allow for a safe landing. Look at you hydrualic schematic and see which system powers what and you'll see the specifics as to what the blue powers...
RD