RE: Spark plug color?
Looks okay to me. Might be just a teeny bit rich. I like my plugs a bit more tan. But, it could just be the lighting or the angle of the camera lens.
How does the top of the piston look? You got the plug out--pull the muffler if it's easy and look at the piston. Check the rings to make sure they aren't seized in the ring grooves. You should be able to see them just barely moving up and down as you twist the crank back and forth. That means they are floating good and not seized.
Check the cylinder walls through the exhaust port. Get a tiny mirror and slip it inside the exhaust port. Shine a light in there and look around.
I think it's probably fine. Reading plugs is so subjective. Depends on who is looking at it. I'd probably run it a couple gallons with that plug and pull it out again. If it idles good and transitions good--don't mess with it. Most engines will act a little fussy on initial start up when the bottom end is leaned out enough. They need to warm up for a minute or so before they will throttle up clean and snappy. If you can start it cold and get perfect transition out of it when it's cold--the bottom end could be a little rich still. It doesn't take much tweaking to get it either perfect--or screwed up.
I'd run it for a little bit longer and check it again in 1.5 or 2 gallons. If it ain't broke -- don't screw with it.
Just my humble opinion. [8D]