This paper reports on the colorimetric improvement of a multispectral 3D digitizer through scanning at optimized wavelengths. These wavelengths were first established theoretically based on the criteria of minimal CIEDE2000 color difference over the set of reflectance curves from the full OSA-UCS catalog. A PCA-based and a spline-based spectral estimation method were considered, and sets of three, four and five optimal sampling wavelengths were derived for each method. This provided a basis for the selection of HeCd, ArKr, HeNe and DPSS commercial laser lines for which the colorimetric performance was predicted. This was then tested in the lab, where colour rendition charts were scanned with the camera at seven wavelengths, after which the charts were computer-rendered on a CRT display. Both the theoretical prediction and the experimental observation indicate that four well-chosen wavelengths are adequate for proper rendition of the charts.