The 'tan' part isn't of note. It's not the color of the insulator tip (which would pretty much only give you an idea of plug temperature anyway) but of the mixture ring (which would turn a darker color if it was run longer).
As you say, it's still wide if it's 'correct' jetting your looking for (given a correctly run WOT plug chop test).
And, yes...a 42:1 premix will be more lean. I haven't done plug chops on different premixes to be able to say from my experience what degree of change you could expect by way of plug inspection. Considering it's a 15% drop, I would think it would make a fairly big difference.
If your carb hasn't been modified, a 1/2 turn out on the airscrew is an indication of your pilot being on the lean side already. Set the pilot circuit using throttle response as a gauge.
Plug loading at lo rpm can be resolved with a needle change. A sharper angle means a 'later' starting taper. I've had much better luck keeping the plug clean with a 'C' taper.
twocycle: Keep in mind that a plug heatrange change is not the way to 'effect' jetting (effect in '' cuz of course it doesn't 'effect' it at all).
If you do happen to get to a too-high idle on a choke-cold start, regulate it with the kill button. A bike that is lethargic when cold (boggy, poor throttle response) isn't necessarily a bad thing. If it runs OK when it warms up, it's actually a good thing.
A situation of, 'Starts first kick every time,' probably is from a too-rich bike.
re: will a lean pilot hurt anything?
It might if you have to kick it so long to start that your leg falls off. ;)