You're on the right track. There are the three pinkish/red fluids our cars have.What does it smell/taste like? Coolant is more watery, and smells kinda sweet. Whereas power steering (especilly if one used ATF to fill it is oily, and smells ... weird.
The other fluid you didn't mention is your transmission fluid. Many use transmission fluid for power steering, so that fluid could be the same, and you'd have to determine the source of said leak.
You're not guaranteed to leak coolant if the water pump is dead or dying. Same goes for power steering fluid or transmission fluid.
With coolant, usually wherever it dries gets white crusty's. Power steering and tranny fluid typically just attracts all of the dirt and grime and sticks to it, simliar to oil.
Pull the transmission dipstick. Is that fluid low? Look at the power steering reservoir. Is it low? Coolant reservoir-- is it low? If so, that again, would help determine what is leaking and where the source is.
Best bet is too look under the car and/or hood and determine the source of the leak otherwise it's a crap shoot and blind diagnosis.