leak fluid from back of car

What color is the fluid?

water is from A/C green is coolant (it also comes in red)(consistancy of water) red/brown could be trans, or power steering gold/brown could be oil, or from differential <<<<< if its a sticky oil, its brake fluid<<<<< but Im sure there are other collers out there being used just now seeing it says back of car, it might be differential or brake ffluid