According to the folks at Tribeca Imaging Laboratories (TIL), digital cameras (and I might add many types of film) "can't see purple." They go on to say, "The digital color model generates a limited spectrum. Any user can confirm this by simply pointing a camera at a deep blue or purple object and comparing the colors on the camera's LCD or computer screen to the original subject."
While those of us who have tried to photograph chrysanthemums on film in the past know about this purple thing, the TIL crew decided to do something about it. They conducted years of research and came to the conclusion that the issue is not camera specific. Indeed, they concluded that the limited spectrum response was common to all digital cameras, dubbing digital color "universally inaccurate." Their response is the DCF Full Spectrum plug-in for Adobe's Photoshop, which works on both Mac and PC platforms. They claim that by using DCF Full Spectrum in Default mode that the photographer will get the most accurate possible colors from digital images, shot in sRGB or Adobe RGB.