The shot was grabbed from a version of the Luigi Cazzaniga NIST release. That version contained an added sound effect and truther who apparently made it thought he could fool us into believing the event was genuine. It was thoroughly trounced and the truther took it down. It's discussed here:
http://www.internationalskeptics.com/forums/showthread.php?t=188116
In fairness, the YouTube you link to does have an excerpt of the Cazzaniga video, about three seconds of it. I wonder why.
Full clip:
http://www.youtube.com/watch?v=bF2YPGb-LYc
Grabbed from the Cazzaniga NIST release:
[qimg]http://i1233.photobucket.com/albums/ff387/AJM8125/Cazzaniga46A.png[/qimg]
Ooooh. Shiny.
I don't know what to tell you. It sure looks orange to me. Here is the full NIST FAQ don't you think they would have mentioned if it were silver?
11. Why do some photographs show a yellow stream of molten metal pouring down the side of WTC2 that NIST claims was aluminum from the crashed plane although aluminum burns with a white glow?
NIST reported (NCSTAR 1-5A) that just before 9:52 a.m., a bright spot appeared at the top of a window on the 80th floor of WTC 2, four windows removed from the east edge on the north face, followed by the flow of a glowing liquid. This flow lasted approximately four seconds before subsiding. Many such liquid flows were observed from near this location in the seven minutes leading up to the collapse of this tower. There is no evidence of similar molten liquid pouring out from another location in WTC 2 or from anywhere within WTC 1.
Photographs, and NIST simulations of the aircraft impact, show large piles of debris in the 80th and 81st floors of WTC 2 near the site where the glowing liquid eventually appeared. Much of this debris came from the aircraft itself and from the office furnishings that the aircraft pushed forward as it tunneled to this far end of the building. Large fires developed on these piles shortly after the aircraft impact and continued to burn in the area until the tower collapsed.
NIST concluded that the source of the molten material was aluminum alloys from the aircraft, since these are known to melt between 475 degrees Celsius and 640 degrees Celsius (depending on the particular alloy), well below the expected temperatures (about 1,000 degrees Celsius) in the vicinity of the fires. Aluminum is not expected to ignite at normal fire temperatures and there is no visual indication that the material flowing from the tower was burning.
Pure liquid aluminum would be expected to appear silvery. However, the molten metal was very likely mixed with large amounts of hot, partially burned, solid organic materials (e.g., furniture, carpets, partitions and computers) which can display an orange glow, much like logs burning in a fireplace. The apparent color also would have been affected by slag formation on the surface.
