Transmission pressure?

2006 Prius with 130k miles. Bought at around 115k and it had been serviced at a dealer with new brakes, oil change and ???

I decided to change the trans fluid now that it has 130k since I was unsure how old it was. The car was about as level as can be expected so I jacked it up in front to loosen the fill so I could slowly lower the jack to find out what the starting level was as added precaution. As soon as I broke the fill bolt loose I could hear air escaping and as I loosened it more the fluid shot out. I got about 1 cup in the catch pan and lowered the jack to level the car and ended up with 2 cups. Initial thoughts are it was roughly 2 cups over filled. Has anyone ran into this pressure situation or could it have built pressure due to being too full?
Secondly the fluid looks nearly has red and clean as the new fluid so I am inclined to just tighten the fill cap and wait another 15k miles.

Thoughts?

 

I thought of that but doubt it settled out that perfectly that the top is like new and bottom is not, although I am sure the heavys are at the bottom. If I went that far to drain off the bottom, I would just change it out, but based on comparison to the new I think I will hold off another 15k.