Color print out with pxlcolor very distorted Please see the description on launchpad https://bugs.launchpad.net/ubuntu/+source/ghostscript/+bug/510832
The PCL XL driver is not rendering-intent aware (bug 690867), possibly until Michael finishes his color related work; I cannot see anyting obvious wrong with that the PCL XL driver is doing wrong currently though.
In light of bug 691082, any chance of a re-visit on this? The current PCL XL driver output may not be color-accurate, but I don't expect it to be too far off - small color shifts, somewhat different contrast. Gradients can possibly improved with WTS. I am a bit concerned about "color gradient tables, sometimes adjacent colors, which according to the nature of a gradient should be similar, are of entirely different color or even black" - if it is white text on color background, etc, it could be one of the bugs that were fixed recently - the next ghostscript is just days away but you are wellcomed to try svn or just wait a few days for the rc1. OTOH, when I was looking up some on-line tutorials about WTS to point you to (foo2zjs provides some), I noticed that foo2qpdl (http://foo2qpdl.rkkda.com/) supports Samsung CLP 610, and yours is 610ND - you may be happier using foo2qpdl, or at least borrow some tips, or the icc-related instructions from there if color-accuracy is important to you.
As the CPL-610 printer definitely has issues with the provided PCL firmware, I think I will better not investigate further in the pxlcolor driver - any report would be meaningless unless a stable hardware can not be proved. I filed a report to Samsung; While I doubt they will provide me with a PCL firmware update, I will certainly investigate and come back to this bug. Unless it may be closed. Thank you for the links!
I am not sure what can be done if at all, so closing for 'LATER' - there is some serious firmware bug with the printer itself; Michael's color architecture work will improve color reproduction; there are also some issues with B/W text on color background where the background is mis-printed which was fixed after 8.70, so the upcoming release due in the next few days should address that; for smooth gradients, tuning WTS helps. Without a scan/digital photo, it is difficult to see which issue this is. Suggest revisit if/when Samsung provides firmware update for bug 691082 . Meanwhile, try with a different PCL XL printer, tuning WTC, the upcoming release or svn HEAD. If the color is a little off, file it under 'Color' for Michael; if the color is not even close (red goes to black, black text white/disappearing, etc'), please file it under 'PCL driver' and it comes to me.