I don't think there will be any issues with it, but if it's available to you, I would take it to a shop and have it flushed. This will get rid almost any residual PS fluid which might be left in the system.
Did you run it with the PS fluid in the reservoir before you changed it? If you just dumped it in, then drained it from the pump before you ran it, then you'll be just fine. If you did run it, it will need to be flushed. This is not something you can easily do as a DIY and get all of the PS fluid out, for a lot of reasons. But if you are insistent on doing it, this is what you'd need to do:
- Put the front end up on jackstands.
- Put a drain pan under the steering rack
- Pull the return side hose from your PS pump, letting it hang down below the steering rack and into the drain pan.
- By hand, turn the PS pump until all fluid is pumped out
- Turn the wheels by hand (lock to lock), back and forth until no more fluid comes out of the PS return hose
- Reattach the return hose
- Fill the reservoir with Dexron III fluid
- Turn the wheels by hand (lock to lock), back and forth several times
- Top off the reservoir
- Start the engine and gently cycle the steering back and forth, lock to lock ... DO NOT CRAMP THE STEERING!! (Cramping is where you continue to put pressure on the steering wheel at the end of the range of motion --- you can hear the belt squeal)
- Repeat 9 & 10 until you no longer need to put fluid in it NOTE: DO NOT OVER FILL
- Put the front end back on the ground
I think this will get you done. There may be a slight residual in there, but nothing you'll need to worry about.