Spark plug is yellow

[Racerx63]

I just did a top end on my 250R and after breaking in the motor I did a plug chop. On the top end run the plug was Yellow. I have never seen this color before. It is usually black, tan or White. I did a search and they said that color is a lead foul. Is this color bad or is it ok to run.

I am running 50/50 F&L 111 octane and 92 octane with MC-1 50:1.

Thanks