Re: How to print photos with correct colors - color management, darktable and gimp
What printer, and are there any adjustable settings on the printer itself?
When I originally got a Lexmark C543dn color laser, I thought that its default colors were too bold, which may be fine for attention getting brochures, but not photos. So I downloaded a reference image that was a combination of various images and used up some toner adjusting the printer itself until everything in the print looked photo realistic to me. So it works perfectly in Windows or Linux.
When I got the same printer for the office to replace an obsolete inkjet printer, I set the new C543dn to the same settings I worked out at home, and it was picture perfect just using settings on the printer itself.
So I would get an unaltered combo reference image and adjust whatever you need to for that to print perfectly. Then adjust your monitor settings to have it look the same on your monitor.
The only thing I normally do with gimp, other than scaling, is Colors > Curves, not to change colors, but to brighten up dark areas or smooth out high contrast. I am not a pro, but have been taking pictures for probably 50 years.
i5 650 3.2 GHz, 8 GB, nvidia GTX 550 Ti 32" 1080p | i7-4700, 8 GB, Intel HD 4600/nvidia GTX 765M 15.6" 1080p | etc.