Just picked up my new 642. Everything looks great, with the excpetion of the trigger. It looks "dirty", but nothing wipes off, so I'm assuming this is how it's supposed to be? I know its only cosmetic, but just didn't look like I expected.
I think it the pics make it look not as bad. In person, the whole trigger is very discolored. The entire trigger is almost completely dark grey colored.
If you notice it's pretty much the same color as the cylinder which is stainless steel while the frame is aluminum alloy. That's why there is a contrast.
The finish you see is meant to mimic color case hardening. True case hardening provides a much more attractive and colorful finish than the current process.