Spark plugs have a thinn white coating on them......whats that mean?

i just bought my 96 black camaro 5spd v6, has 110K miles, i took some spark plugs out to inspect them, they all have a thin white coating on them, whats that mean, fuel too lean?

burning hot/lean

they werent shiny were they?

no, definately not shiny, im guessing that motor overheated once because when i bought the car, i noticed the water pump was like brand spanking new, should i change the plugs, that might be why my damn mileage is sucking

it never hurts to change em