Hi Chuck,

Some of the members are using 160 mains.

When you are looking at the spark plug color,
"To get a true plug color reading you must run the engine,on a level road, at the throttle setting that you want to test, for about a mile, then kill the ignition, pull the clutch in and coast to a stop. Then pull the plug and look at it. This could be a real thrill on most of the newer street bikes."
excerpt from Dan's Motorcycle Page: Spark Plugs

Dan's Spark Plug reference chart

The NGK Iridium spark plugs should be true to color. These plugs should not burn hotter, instead they are at least theoretically more efficient. (I could stand to be corrected on this point though.)

Blowing gravel off rural roads