I have been watching a video showing AAVP7A1s in the hold of USS Pearl Harbour. I notice that the track links are a distinctive brown colour. What I am not sure of is whether this is simply corrosion or the colour of the metal used for the tracks. Had this been due to rust, I would have expected the colour to be patchy. Instead, it appears to be a uniform colour. Any ideas?

That distinctive brown color is most probably rust, they tend rust extremely quickly. We could spend all week in the field running around with the tracks getting nice and shiny, or at least that dull steal color but approximately 5-seconds after parking on the ramp after the op they would start taking on that light orange tinge until after a day or two they were that nice dark brown colored rust. Totally normal on AAVs, considering their operating environment of constant exposure to salt water.
Couple pictures from my time around AAVs and you’ll see that every AAV in the pictures have that protective rust coating on the tracks.