Spark Plug Question

[L J VFR]

Put new plugs in.  Rode about 100 miles..  Took them out to check them..  The plugs look good, whitish brown on the electrode. However, the rim  is black. On all the plugs..  Is this normal??  Is my bike running to rich?  I can take my finger and wipe it off of the rim. Carbon buildup?? 

[L J VFR]

Carbon Fouled

Soft, black, sooty deposits easily identify this plug condition. This is most often caused by an over-rich, air/fuel mixture.
Check for a sticking choke, clogged air cleaner, or a carburetor problem - float level high, defective needle or seat, etc.
This may also be attributed to weak ignition voltage, an inoperative preheating system (carburetor intake air), or extremely low cylinder compression.
             http://www.verrill.com/moto/sellingguide/sparkplugs/plugcolorchart.htm                     Mine looks like the carbon fouled ones, just on the rim though..