Originally Posted by 375inStroke
Some Alodines do turn aluminum yellow orange, but some don't, like Alodine 1000, and are made to stay clear, like on polished fuselages. The old American Airlines, for instance.


Agree, 1001 is close to not changing color, but does to a small extent.

As for A/C exterior skins, those are Alclad (a very pure form of aluminum used for its corrosion protection) and no Alodine/Iridite is used.