I have the same engine and, no, the #3 spark plug is the same as the rest. I did have a bit of trouble with #4 on mine because they were original so a bit of corrosion had built up on the threads.
Your pic doesn't look too bad. Maybe running a little rich.
Give her another try, maybe she is just being stubborn.
Here is a visual chart showing plug conditions and yours looks normal.
NGK Spark Plugs USA
Remember to use anti seize on the threads when you re-install.