I just bought a used t56 from this guy with 68k on it came off a 2001 ss, i was draining the remainder of the tranny fluid out and i noticed that it was pretty dark. It wasnt red like it is suppose to be. Almost like as if somthing were mixed in with it. Kinda dark burgendy i smelled it and it didint smell like ATF so i am not sure on what it could be. I even added some new fluid into the tranny while it was out of the car and when i poured it into the tranny and let it drain out i saw red which is the new fluid then i saw little streams of dark color which was the old. Any ideas on what this could be from ? IE oild fluid ,burnt etc
Also i am going to add new fluid to it in the morning how long should i run the new ATF before i drain it ? SInce it was so bad looking before. Should i even drain it again due to the fact that it was dark ?

thank you !