Spectrum.dat is the file created when a color spectrum is saved for future use. Color spectrums can be saved by right-clicking on the spectrum in the Graphics Area and selecting Edit Deviation Spectrum.
Click on the Save As button in the dialog to save the spectrum to the computer.
To use the spectrum again during a future 3D Compare analysis, select the name of the spectrum from the drop-down menu in the 3D Compare dialog.
Spectrum files are saved to the following default directory:
XP: C:\Documents and Settings\All Users\Documents\Geomagic\Geomagic Qualify **\Data
Windows 7 / Vista: C:\Users\Public\Public Documents\Geomagic\Geomagic Qualify **\Data
To copy a spectrum from one version to another, simply copy the spectrum.dat file from one version's folder and save it to the other version's correct folder.