Olivetti D-COLOR P26 - Manual (Page 69)

Colour matching> 69
R
ELATIVE COLORIMETRIC
This option is best for printing solid colours and tints. Use Relative
Colorimetric when printing from a drawing program such as
Adobe Illustrator, or Macromedia Freehand.
A BSOLUTE COLORIMETRIC
This option is recommended if you are proofing images on your
printer that are intended for final output on a printing press. This
may result in a visible colour cast on your print as it will also try
to simulate the paper white of the target device.