Burning tips off plugs

O.K. here is a plug after 3 passes, they look awesome.No little balls or metallic on them, but then again, it is only 3 passes.The exhaust looks perfect, biege.
I went to a colder plug. We will watch them this year.
Answer to fuel.....Sunoco 110
I am 12.5 compression.
P.S. That is greese on the porcelain