On the ground with Skin temperature below +12c, the AEVC computer will command the INLET VALVE to be closed, and the OUTLET VALVE to be open. When the VENT EXTRACT PUSH BUTTON IN OVRD the AEVC will close the OUTLET VALVE, and the INLET VALVE will remain closed. In the case of the OUTLET VALVE the Amber indication indicates an incorrect valve position to what is normal. The INLET VALVE remains green because that is what the AEVC is commanding it to.
Therefore, if the Skin temp is above +12c the INLET VALVE and OUTLET VALVE would be open. Pressing VENT EXTRACT PUSH BUTTON IN OVRD would close both valves and then they would both be indicated in Amber.
Hope this makes sense? Although it ultimately depends on aircraft effectivity