Plug reading has become way more difficult than it once was. Reformulated gasoline, even the ethanol-free flavors, is very different than it was when these bikes were new.
IMHO, the coloration of that plug looks pretty damned good. It's mainly a question of the running conditions that produced the color(s). Old-school plug chops are kinda tough to do, without a test track (improvised, at least) where you can run through the gears at WOT, pull in the clutch & shut off the engine, then remove the plug for a reading. That, imo, is the second-best methodology, after EGA, using a wideband O2 meter to tell you the A:F ratio in realtime. Fortunately, neither of those are absolutely necessary.
For the sake of brevity (and the sanity of most who might be reading this) I'll cut to the chase. Starting from scratch, I find the rich limit...that means the largest main jet that will allow the engine to rev-out cleanly at WOT. At the rich limit, the next size main jet, or just one jet needle groove richer (lower groove for the C-clip) results in rich misfire. That, typically, gets you to within one jet size and 1-2 jet needle adjustments of ideal. It's nearly as simple (though a bit more tedious) as it sounds. The only potential wrinkle is when you have to choose between two main jets, with very different jet needle settings; don't lets go there right now. Since you're working with the supplied carb, test different jet needle adjustments; that, alone, should do the trick. I've yet to see a basic 110/125 engine "kit" with an oversized carb, or the wrong jetting. It could happen and there's always a chance of hitting the bad luck lottery and ending up with a defective carb, it's just very unlikely. They all seem to come with ~18mm (actual size) venturi carbs, which means high airflow velocity, easy tuning and few intractable problems. To limit power, a carburetor has to be seriously undersized...and 18mm is not grossly undersized for 8-10 peak hp.
If you suspect that the mixture is lean, move the jet needle C-clip to the lowest groove and see what effect that has. Hopefully, the mixture will be too rich, in which case you'd drop it one groove and retest. You'll find the best setting, using the old, reliable, seat-of-the-pants dyno. It really is that simple. there's only going to be one best setting and, at most plus/minus one groove in either direction that even comes close to working. This is mostly a matter of patience. It can take some time to fine-tune your senses to recognize what's going on but, once you do...you've become your own carb tuning expert.
It can be surprisingly easy to confuse rich for lean. Overrich mixtures tend to result in easy cold starting, strong throttle response, black exhaust smoke (in some cases) and rich misfire at WOT before the engine can rev-out. Lean mixtures tend to manifest as weak throttle response, hard starting when cold and having to feather the throttle to get the engine to rev out, if it will at all.
