in Feb I replaced my spark plugs (WR7DC.) 3,000 miles later, I pulled them to inspect, and 7 have a consistent light tan
color, and look "normal." the remaining plug, (from #2 cylinder) was very white. various searches say this reflects a lean condition.

I am not experiencing any discernable symptom(s). what symptom "should" I be seeing, with this issue?

could this be a faulty injector? and if yes, would the fault be on the fuel side, or the electrical side? nearly certain,
that these are the original injectors and have never been serviced.

are there other situations that can cause a very white plug?

 

A very "clean" plug can also mean a leaking head gasket.
Hope it's not the case.

Any pics of the plugs?

 

unfortunately, I tossed them.

pretty sure that's not the case.

 

Dig them out of the trash, one of them will be different from the other seven. That'll be plug #2.

 

This might help.

 

from left to right are plugs 1 thru 4




here are plugs left to right 5 thru 8

 

hmmm if not a head gasket leak then replace the fuel injector......

 

car runs well, no overheating, no oil in water, or water in oil, lots of power.

what symptom(s) or what should I look for, if there is a leaking head gasket?

 

My first guess is also injector.
Could also be a bad plug or plug wire.
Most head gasket leaks will leak more pressure into the coolant than into the cylinder.
To check head gasket leak;
1. Hook a pressure gauge to the coolant system, crank the engine over half a dozen times without starting the car, see if pressure rises
2. Pressurize the cooling system overnight and check for leak down and moisture in the cylinder.
3. Compression test on all cylinders.