mine is only white when i clean it ...
any filter cleaner and oil should be fine.
I use k&n filter clean and oil ...
If it is really dark in color, you may have oiled it too much. I never tried the cobb oil, but you should only put a even light layer of oil and let it dry for about 30mins to an hour. Over saturated filters will suck that oil in and get on your MAF sensor which is a big .. no no
Oil on the MAF can cause studdering, stalling and rough idle. Even not starting.
It can be cleaned, but MAF sensors are very sensitive due to that they measure air. A new MAF will most likely range 300-400 bucks and up. Not sure how much for our cars, being that they are pretty new.