Hi there !
(I have previously had this issue, and in the past it was resolved with trashing my preferences via the "Preference Manager" from Digital Rebellion, but that doesn't do the trick any longer)
I always use FCP's 3-way color corrector on my Pro Res footage (shot with a Canon 5D DSLR), I choose the Black, then the White & then manually play around with the Mids until it makes sense.
On my iMac everything still works perfect, but even since I formatted my MacBook Pro, whenever I click the Black or the White it seems to be too extreme, for example I click on something that is absolutely black in the canvas, and then my footage becomes very green-ish, or very orange-ish. I have tried clicking on the same exact spot of the same footage on my iMac, and it doesn't do this, there's only a slight change in color, the way it should be.
I can't quite figure out what I'm doing wrong, as before formatting, I had the same results on both the iMac and MacBook.
I know that for best results broadcast monitors are suggested, but I've been working like this forever and have been satisfied, it just doesn't make sense that recently the 3-way correcter is so OFF.