I personally never bought into the whole K-dust still in his bloodstream thing in LW. If any K was in his system, it would have killed him. Look at how small of an amount got into him in TC, and he nearly died before going into the radiation chamber thing.
My theory on LW is that the green did cancel the K, but only because of the effects the two had on his body. Contact with the green makes him lose his powers. So the very fact that it touched his flesh/blood cancelled out the effects of the red. But none could have possibly gotten into his system and left him alive.
