Posted by Mark Krebs-2 on Jan 04, 2017; 3:05pm URL: http://imagej.273.s1.nabble.com/Colorspace-conversions-tp5017834p5017835.html
Hi Rainer,
Perhaps you already know of it, but did you look at Color Transformer 2 and macros that use it? The plugin should at least allow conversion from RGB to other color spaces.