I thought that you were also to look at ground strap and it should change color right at the bend. Any farther down to threads is getting hotter?

Which hole did you pull it from?

Yeah that is going to be impossible to say. I did not even look
at them until I got home. I was going to clean, sand and
re-gap them for the Spring when I first noticed how clean
they were.
As far as proper plug reading procedures go, no I did not
follow them. From what I gathered from the articles I printed
out you should do a full speed pass then turn off the ignition.
Then read the plugs. No idling or slow running allowed. Then
look for the indicators mentioned. I was always taught to look
at the porcelain and see if it is light to medium brown. If it is
then you are good to go. Obviously there is more to it than I
thought.

That is correct also. In his pic, the burn line is right at the bend.