Modern Vespa

Interesting plug color....
VBB, 150 miles on new 2-port, Valvoline dino 2-stroke oil

NGK B7HS

Pistachio?

Oxidation from overheating

Hmmm, I really do not think I have pushed this motor at any time. Everything's stock and the timing's at 28. Should that be any different with the new flat-top piston / cylinder ?
I've got another plug in there and I'll keep an eye on it.
The flash made that seem a bit brighter than it really is and what look like little balls of metal are not.

Plug’s just giving you the green light for thrashing…

I'll admit I've never seen a green Vespa plug, but I worked on cars for a bazillion years and that's a sign over overheating in cars...I can't imagine it's different for scooters. You may trying running a cooler plug version.

this could be an additive package in the fuel or possibly the type of 2T oil you're using. especially if you're not really flogging it, the motor won't get hot enough to burn off all the crap.

as an abundance of caution, I'd switch to a B8 and see what your run is like.

If you've gone from a deflector piston to a dome piston the timing s/b changed from 28 to 22 degrees.

I , too, have never before seen a green plug in any kind of motor in the past 55 years. May be the Valvoline... I'll run another tank of another brand of dino and then switch to semi-synthetic and then my usual Amsoil.
I will also dial back the timing.
And no, I have not done any flogging on the first tank. I must say that do like the 8" wheels.