I wish that sticking a G7 stake was the answer. As an offset/digital house, we support the G7 initiative, though we disagree with certain chromatic values in the magenta and the offsetting adjustment in cyan to compensate for it. It leaves a very thin line to hit without getting a green cast in your work, though that obviously serves as a wake up call to take a look at your system if it happens...
G7 and G7 digital are two different worlds and even deploying into G7 doesn't address the problem. The problem is that the red values of the C8000 and virtually any other digital device have been "chromed" to a much brighter red than true magenta. This is awesome for the creation of direct mail. It does mean that the red values, if they stray more than delta 2 or 3, will create a larger than normal visual discrepancy, and the non-process magenta means a chopping of the color spectrum available against certain offset colors. It also means I have availability of some color gamut I can't do in offset.
The C8000's controls will not control to delta 3, at least not in this machine. At current, it will not control to delta 5, which is a G7 requirement. This is with a statistically significant sampling base. If you just spot check it, you probably aren't getting a true reading, and in reality, aren't G7 compliant. I'm not saying your not compliant, just that digital devices propinquity to stray means you have to employ a similar or even greater sampling method than on offset. And digital company that says otherwise should be avoided like the plague.
And please don't feel I am against digital or really KM for that matter. Just that digital devices get sold as "presses" and they aren't.
FYI, our workaround to date on this has been to run the very crude 600 dpi only stochastic screening on board the Creo rip. It's a very bad workaround, but since we have been unable to get resolution from support in this area of the machines characteristics, but it's the only thing that has worked. It it won't work on non-solid build colors, as the dot routine is too rough for true images. Another sad shortfall on what could have been a great 2400 dpi machine. But, what do we expect from a copier company?
We run daily calibration, btw, so we have eliminated that as a fix for the color shift problem. It exists almost sheet to sheet in this case with certain colors and builds. We do deploy custom customer builds for certain jobs as well, as this is the only "workaround" for problem on the profile side.
Certainly wish I could spend more time running sheets than managing around problems, but it is what it is.