I think thats probably a tough question to answer....... ideally you adjust both, but you dont have that option.
If you had a calibrated display you could attach the dvd player too it and then recalibrate with only the dvd player settings. Then move the payer back to your projector, retain its settings and now calibrate again but using the projectors settings...... this would ensure both are doing what they should be.
I doubt that is an option mind you! were it me, I would leave the dvd player at default and fiddle with the projector. I think the dvd player is much more likely to be correct
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