On 2 and 4 cylinders the header coming off the block are blessed. Wouldn't bother me if all four where blued but only two are. Is this some thing I should worry about?

It's a 06 fz1 k&n filter secondary throttle plates out, with slip on and gutted cat converter. Again, I've herd it's normal sometimes but, on just two cylinders??

 

Do all the plugs look the same? If so don't worry about it. If not you'll need to investigate some more.