well, the plug looks like its runnin overly rich. its hard to see how hot its runnin but sorta looks too hot. the browning on the porcelin almost looks like carbon melting and getting glass like or like stated before the fuel additives discoloring it. the strap is too discolored to tell you about heat range as well.
oh, and fix your oil leak. oil shouldnt be on the threads.
but in all out honesty, ive scene alot worse. those arent that bad.