I have found a new statement in the world of Naruto. I was watching the episode where Pervy Sage forces Naruto to use the Nine Tails Chakra for a summoning jutsu, and in a slightly earlier episode, Naruto described the “strange” chakra as red. After further research, I found that the Nine Tails original Chakra was orange [(its color gave it away easy) plus Naruto in Nine Tails Mode is yellow, when he looks like the Sage of Six Paths]. This led me to believe that the Nine Tails has duel personalities inside Naruto. The only one shown being the Red Nine Tails (it’s Spiritual Chakra).
   The Yellow Nine Tails (it’s Physical Chakra) I believe is actually integrated into Naruto’s own Chakra network. This is explained not only by his mother’s Uzumaki heritage, but also by his healing factor and his abnormally high stamina and chakra. The reason it is not seen taking over his body is because it has naturally adjusted to Naruto’s love for awesome Ramon (lol). Not only that, but the Yin (Black or
in this case Yellow) side of the Chakra is represented as the Positive side of chakra, therefore a possible Positive personality.
   Therefore, the reason Naruto starts transforming into the Nine Tails is because the more Red or Yang Chakra released, the more balanced the Chakra becomes, slowly transforming it back into the Nine Tails. But due to the Yellow Nine Tails adaptation to Naruto’s Body, the Red Nine Tails takes over his soul (mind, will and emotions; starting with his emotions then moving to his mind, and then his will).
   If anyone has any questions, then reply to this post, and I’ll see what I can do.