Spark plug color - how to diagnose

Hi. I have Iame Leopard RL TaG 125ccm engine. Tillotson HL334a carb settings with Jetting App. Its my spark plug after six sessions, fifteen minuts each. What can you say about this plug ?

Looks good to me. Somewhat Chocolate Color. Too light would be on lean side, too dark would be on rich side.

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