I have solved this problem by Compressor.
I had a same issue on my iMovie, but when I convert the clips to same H.264 video, it worked fine.
No red tinting occurred to any clips.
The exact setting I have used is follow.
Apple devices / Apple Devices HD ( Best Quality ) / Best quality
I haven't tried other setting but I think any of them should work.
After the conversion is done, the "kind" will become "Apple MPEG-4 Movie" instead of just "QuickTime Movie" which originaly was.
I know it's going to cost you extra, but if you already own Compressor, give it a try.
PS
My FInal Cut Pro X didn't require any conversion.
Is it because I have upgraded to 10.1?
Have fun!