Thanks again. Can you give me some more informations? Where can I read more about XYZ negative values? I'd like to understand more, if possibile. Vittorio From: ib@xxxxxxxxxxx Subject: [argyllcms] Re: ccmxmake: some questions. Date: Wed, 4 May 2011 16:54:54 -0400 To: argyllcms@xxxxxxxxxxxxx Dear Vittorio, Can you please tell me if the XYZ values can also be negative? Yes, Device XYZ values can be negative. For what I understood they should start from 0: http://en.wikipedia.org/wiki/CIE_1931_color_space. What am I missing? You are missing nothing, WiKi is wrong here. Not your fault. --Iliah Borgib@xxxxxxxxxxx