Unlike other CAD software, Creo present some extra parameters called “Intensity“ for colors.
Or HOOPS, while reading Creo colors, is in fact applying that scale to the flat colors as follow:
HOOPS RGB Color = Creo Flat RGB values * Intensity / 100
As a consequence colors are sometimes enlighten to correspond to how they’re seen in the viewer.
It is however possible to revert back that operation if needed since Intensities for all materials are also retrieved as m_asSingleAttributesData For the answer to this question, check out our forum post.