I had went to the Apple Support forums last night and discovered that hundreds of other people are having this "green" or "teal green" color cast issue too. Some were able to solve the problem by going into the Aperture properties and removing the RAWDecodePresets.plist file and then reprocessing the images. But this only worked for a few folks, not everyone.
I tried reprocessing them first, but it says that I don't have any images to reprocess (presumably because they've already been reprocessed to Aperture 3). Then I tried removing the plist file as described above and then reprocessing the images and that didn't work either. If there's one common theme amongst nearly everyone (but not all), the problem seems to be with 30D RAW files that were processed and edited in Aperture 2 and then reprocessed in Aperture 3. The problem for me is that I have over 10K images that have been shot with the 30D and edited in A3. I can't afford to have a large chunk of my library "green".
I'm probably a little emotional towards this because I was so excited to get my hands on A3 and then I literally spent all day yesterday loading, reprocessing, and then troubleshooting this issue. Now a good portion of my library looks terrible, and is completely unusable for many of the projects I'm working on. I simply can't afford to just put my 30D pictures to the side and move on.
I am totally open to suggestions and hopeful that someone else has found a way around this, but I can't figure it out within a few days, then A3 will have to go. I'm a huge Apple fan and have never had an issue with any of Apple's products, but this one is really letting me down, especially since it is a pro application.
Bryan