Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

Robin Unger put up this frame from the Zapruder film showing that there was, indeed, quite a bit of pink reflection onto the chrome molding. 

Notice also the pink reflection on the chrome plate that is on the inside panel of the car. Here it is from frame 264: 

Also frame 283:

That is quite a big flashy display of pink, isn't it? Look where it is in relation to the window frame.

It's right next to it on top of the ledge of the car. 

Alright, so now, let's look for that on the disputed photo.

The area in question is obscured. Is it pinkified on the other side of her wrist? We can't tell from looking at this. 

Note that in the disputed photo the molding has taken on a purple color while in Zapruder, it's pink.

Is that due to different lighting, different camera, etc.? Maybe, but then again, maybe they photoshopped it purple. 

But, the bottom line is that it doesn't matter because, biomechanically,  it doesn't work for this to be her right arm or her left arm. It's her freak arm.