Gibson actually left the underneath of the pickguard natural so the firestrip would show.
At least that's what i found out.
This link in the comments below state that.
http://pickinparlor.nationalguitar.c...518/51645.html
......The pickguard looks lighter because Gibson always installed their pickguards over the sunburst finish,
but on the black L-00's they left the pickguard area a natural wood underneath so they really pop out at you....