You are right it is tranny fluid in that system they used it in the factory installed steering for years and may still it works just as well as the clear seastar fluid and is a lot easier to see if you develop a leak in the system. You do need to figure out if you can where the fluid was lost at and it will be a lot easier to take it to the dealer and let them bleed the air out it is a 2 man job at best, whatever you do do not fool around if the system has a leak get it fixed cause losing steering is a very bad ride or worse. Good luck Larry P.