Power Steering Pump - oil replacement
 

Recently looked at the PS fluid - after 89,000 miles thought it might be due. The PS was operating without issue.
My, my, I am suitably embarrassed. dark red and almost opaque.

Bought a can of the recommended oil. Since I had plenty, and it was light green and clear, I decided to drain, drive, and repeat until the can was empty.

Now I have emptied the reservoir 3 times so far and the stuff I suck out doesn't appear very different from the first batch.

What is the total volume of the system?
Should I just find out how to flush the whole thing at this point?

thanks for your opinions, guesses, and outright knowledge.