Dodgy FS100 highlights? Have you tried FCP's 'desaturate highlights' filter?
 

Hey guys,

I'm not sure if this is common knowledge or not, but I've just begun some preliminary edits on a corporate I'm shooting, and glancing over FCP6's video filter options noticed 'desaturate highlights' for the first time. I'm working with with 10-bit ProRes from an F3, but the filter looks like it could be just the thing for those nasty, colours that come up in blown highlights on the FS100. It's also an incredibly fast fix, just drag and drop (or at least it is with ProRes).

http://i.imgur.com/HyNqL.jpg

http://i.imgur.com/CnTka.jpg

I've also learnt that I seriously need a more colour-accurate monitor for recording, because none of the yellow cast that's on the original F3 footage was apparent when we shot it