This seems like a rudimentary problem I'm having, and yet I can't seem to resolve it...
I recently cut a music video shot on the 7D. The files were converted to ProRes 422, and I AMA'd and transcoded them into Avid 6.0.
Now, here's what I'm having some trouble with. I purchased myself a copy of Magic Bullet Looks, and thought I'd give that a go on this. Finish everything in the box, since its just going to web anyway (not my usual preferred workflow, but I thought I'd give it a go).
What I'm noticing is that there's a massive color shift. More than I'm used to. If I export the file in any way (even Same As Source) a get a massive color shift (most noticeable in the reds). Now here's the kicker: If I export as a ProRes 422 HQ file, it looks exactly the same as what I'm seeing in Avid. But then if I compress that ProRes file to anything else, boom, it goes back to that color-shifted look.
I'm wondering if some strange color-profilin' is causing problems. I'm not even sure if or when or how it's being applied.
Any help would be greatly appreciated.
Note, I know h264 does it's own bit of color shifting, but this is out of that range. it's a big change.
I ask this because I've noticed a similar (but not identical) issue. I'm working with ProRes MXF files (perhaps same as what you're doing?), and my exports out of MC also exhibit a color shift.
Even a quicktime reference file (from ProRes MXF) will exhibit a change.
The only fix is to transcode my sequence into DNxHD, at which time there is no color shift on my exports. For now you may have to do the same.
My guess on what's going on: The export dialog box gives you the option to output RGB (which takes the 16-235 values and pushes them out to the 0-255 range) or 709 (which leaves everything as is). I think exporting a quicktime from ProRes MXF is always forcing the 16-235 values to be shifted, even if you select the latter option not to do that.