That looks good. Your plugs are working normally.

 

that little bit of rust is normal. Some anti-seize on the new ones will solve that next time.

 

looking more at the torched look on the insulator...

 

That's a corona, caused by the higher voltage that is required by the iridium plug. The voltage difference ionises the air around it (together wiht the dust particles), and deposits it onto the ceramic insulator.