MBP construction question

I'm casually looking at purchasing a MBP or other Apple machine within the next year. I don't have an Apple store in my area, so I'm hoping you guys can answer this question for me: is the top area (palm rest) of the MBP made out of the aluminum that the rest of the case is made out of, or of a composite plastic that is painted to look like the aluminum? I ask because I've read about (and seen) discoloration/paint coming off on older Powerbooks.

Thanks!

 

its definitely the same material as the outside.

 

The discoloration happens on virtually all aluminum notebooks. The exact same effect happened on my D400, and my D610 on the aluminum palm rest area.

 

That's actually not true. I have an older PowerBook 17" and a 15" MBP. The 17" looks just as good today as it did when I bought it 2003. The excessive heat has caused my palms to get sweaty many times and no discoloration has occurred. That has happened in the past to a very small amount of aluminum Powerbooks but that was based on a chemical reaction due to a persons jewelry worn on the wrist.
The Powerbooks B 4 2003 were made of Titanium and they were actually painted so the paint would chip a lot on the palmrests and the edges which is why Apple now uses anodized aluminum.

 

Note how I said "virtually." I realize there are exceptions, but out of notebooks which are available new today, those exceptions are extremely rare. Also, the discoloration does not occur on 100% of affected models. I also personally think that aluminum alloys are more prone to the discoloration effect, though it's been reported on anodized aluminum chassis as well.

 

It does get really hot though, which tends to make your palms sweaty, which tends to leave a lot of unsightly marks on the palm rests. I do find myself wiping it down every day just in case.

 

Its made of aluminum and very thin outer bezel seems to be grey plastic. Nothing that can flake off or get discolored.