Pulled my plugs, I have a question about colors

1993SSP

Founding Member
Sep 5, 2001
1,194
0
37
Ky
Pulled my plugs to step up to a ranger hotter because I think my plugs may be getting blown out during heavy load. Some of the plugs are a grey and some of them are black, not sooted heavy black, just a even black color on them. I probably should have taken the time to write down which cylinders were grey and which were black but I didnt. Any input on this? Does my tune sound like it's ok? Will stepping up to the hotter range plug be a possibility of any problems later on down the road considering the condition of my plugs? I am stepping up from a autolite 24 to a 25.