Just discovered today that 720p DVCPro HD files rendered in After Effects cannot be brought into Color as they are completely blown out. I was speaking with another Cow user and he's got the same issue. in fact, he brought it to my attention.
I also tried exporting Self Contained Quicktime Movies from the FCP timeline, but this made no difference. That really surprised me.
Here's a frame of the original animation as it appears in Final Cut Pro.
Here's the same animation after it has round-tripped from Color. This is also how it appears in the Color timeline.

Fixed! Update to AE 8.0.2
Well, whatever it was, Adobe seems to have fixed it with After Effects 8.0.2 update. I just re-rendered a 5 second test, brought it into Color, rendered it there and sent the result to FCP. now the animation appears normal
Walter Biscardi, Jr. www.biscardicreative.com