Tiptronic fluid color

[Wamiq]

I have a 2002 Boxster. The tiptronic transmission was rebuilt. After driving it for only 66 miles, the tiptronic decided on its own to downshift from 5th to 4th and the speed went down from 70 mph to 50 mph. I pulled over to the road side (HWY 580 East, by Livermore, Ca.) and waited for 5 minutes and decided to get back on the road. When I went up to 60 mph, a high pitch whining noise, followed by a boom noise and black smoke trail appeared. Immediately, I pulled over to the side and saw a whole lot of fluid gushing out. I had the car towed to a nearby garage/shop and had it hoisted. The mechanic took off the cover and found that the differential (?) on the right side (looking from the back side) had a hole/crack. That was the boom I heard. The fluid color was like light barley color. I thought that the tiptronic fluid per Porsche spec, is supposed to be light pink (fresh/new) and over the time, the color changes to darker. Can someone please tell me if wrong type of tiptronic fluid was used or the differential is totally separate from the tiptronic and has its own fluid? Many thanks in advance