WonderWAAAGH: You are only assuming the rules support the second option over the first. There is no rule written either way, there are no real precedents, and whether or not I agree with you about which I way I believe it should go I wouldn't have much to stand on if someone were to argue the other way.
Just like you are. I cannot prove you "wrong" because there are no rules that do so. Neither can you prove you are "right" because the rules simply don't exist.
On our MtG equivalent, let us consider your example. Do you remember Thoughtlace? This was an interrupt (now called an instant) that let you change the color of a spell to blue as it was being played. If in your example you had cast a green creature spell but I had used Thoughtlace to alter it to blue as it was being played , your trigger would not go off. You would be considered to have cast a blue creature, not a green, regardless of what color the card was "when you cast it". Just like my first example allows Adrenaline Rush to alter the maneuver before the red/stress trigger activates, Thoughtlace would alter your green spell before the "cast green creature" trigger had a chance to activate.
The question for X-Wing then is whether or not the change from Adrenaline Rush operates like Thoughtlace does (changing the color as it was played) or if it works as a spell would that only alters permanents.
Lets cross our fingers for an FAQ.