Wow, we have a new thread? Already?
I agree with SeriouslySearching...I think this last picture was taken in more "natural" lighting, maybe even near a window(and, for anyone who hasn't looked, it isn't as sad of a picture as I thought it might be, even though it does show the belt around his neck). Lighting can have a tremendous effect on color, especially when it comes to hair. My own hair color is much lighter than my avatar makes it look, for instance, because I took that picture in low light - we've probably been seeing the same effect with most of Lyle's pictures.
Caucasian "black" hair is almost always really just a very dark brown(and I agree that he looks more like an "ethnic" Caucasian than like a Native American, but wouldn't rule the latter out by any means) - it only looks black because of its great contrast against the color of the person's skin. Whatever race Lyle was, he seems to have had relatively pale skin, and this new picture makes it look like it might have stayed that way even after sun exposure.
Considering the weather, and whether or not it's coat weather...I don't know. To me, it's only coat weather if I'm going to be outside for a long time(and even then, any "coat" worn would basically just be a regular long-sleeve shirt). And he was a man; men don't seem to get cold as easily as most women.
He must have been some kind of magician to make his clothes appear clean even after(apparently) wearing them for such a long time...I have thought about this several times, and all I can think of is that he must have washed them every day and then put them back on(that'd wear them out very quickly, though). His clothes could be another argument in favor of him having had a backpack with him at some point.