Do you know that for a fact or are you just guessing?
If open up the footage on in Quicktime Pro and bring up the Media Info window it states its “Millions” (on any and all computers). Since ProRes444 is 12bit it seems to make sense that it would be in “Millions+” category, but not in the “Trillions” of colors since I think you could lump anything from 8bit to 15bit into the millions Category and 16bit is where it becomes Trillions. But that is a reasonable guess which is only partially substantiated from what I have read elsewhere on the web.
Quicktime and CS4 are all up to date