It's an interesting page, Wire -- thank you. Only 23 unique colors? Now that's food for thought... / Roger -----Original Message----- From: colorsync-users <colorsync-users-bounces+graxx=videotron.ca@lists.apple.com> On Behalf Of Wire ~ via colorsync-users Sent: Tuesday, January 14, 2020 4:48 PM To: 'colorsync-users?lists.apple.com' List <colorsync-users@lists.apple.com> Subject: Re: Humans (and cameras and scanners) do not have a color gamut (?) Searching for layman's info on details of Wright and Guild experiments, I was surprised to find this source. It's webbook that takes on the matters at hand here as related to earth science / oceanography. Ocean Optics Webbook - Photometry and Visibility http://www.oceanopticsbook.info/view/photometry_and_visibility/chromaticity According to the Kelly 1943 projection of the CIE spectrum locus, there are 23 unique colors!