Why does the transmission fluid change to a dark brown or a blackish color when it was just changed recently?
A. The reason it changes color so quickly is that the red dye is temperature related, and if your fluid is changing color quickly, then the transmission is overheating for some reason, possibly slippage in the transmission, or lack of lubrication. If you have this problem then it is time to have it checked out by an independent shop in your area.