[NTG-context] Parameters in \definecolor

Hi all, the manual (the "current draft") says that possible parameters for \definecolor are: r,g,b, c,m,y,k, s, h,t,a,p,e While the first three (rgb), the second four (cmyk) and the third one (s) are pretty obvious for me - rgb, cmyk and greys, I suppose - I'm wondering what is the use of the others? Also, do I get it correctly that if I give all r,g,b,c,m,y,k and s, I will define the same colorname for rgb, cmyk and grey documents, so that \setupcolors[cmyk=no], \setupcolors[rgb=no] and \setupcolors[reduction=yes] (or something similar) will choose only the rgb/cmyk/s components and ignore the others? Best, -- Marcin Borkowski