Today I removed my spark plug just to see how it looked with regards to color. The bike is an '07 YZ250 smoker and the plug is an NGK BR8ES. A while back I re-jetted the bike with a #170 main, #45 pilot, and swapped out the needle for the JD Jet Kit red needle with the clip position set to the 2nd from top. The bike has been running great since then, with no spooge or fouling issues at all. It started today on the first kick after having been sitting for a few weeks. My question pertains to the appearance of the plug. The color is tan on one side, and a light brown or bronze color on the other side. When a plug is running multi-colored like this, what does that mean? Is one circuit still too rich? My pre-mix is a 40:1 ratio of 93 octane pump gas with Amsoil Interceptor. I have included a couple of pictures that will hopefully describe the situation a little better for you. Thanks in advance for an explanation of this plug color. Ron M.