Hi,
If I had to guess looking at the pics, I would say it isn't the transmission. It appears yellowish or greenish and has dried in spots. ATF wouldn't dry.
It appears to be coolant. In the second set of pictures, you attached and circled, I can't orient myself as to what I am looking at. I believe I see part of an o2 sensor, but I'm not certain.
Has the coolant level been slowly going down? Have you tried pressurizing the system?
If you look on the firewall, you should see two heater hoses that attach at the firewall to the heater core which is under the dash. Check around there for evidence.
Here is a link you may find helpful:
https://www.2carpros.com/articles/car-is-leaking-coolant
Let me know. Also, let me know if the transmission fluid is low.
Joe
Thursday, September 1st, 2022 AT 8:19 PM