Max, I know you're interested in better color handling in FOP. I'm currently working on implementing some level of PDF/X-3:2003 support for FOP. PDF/X-3:2003 because it can be used together with PDF/A-1. There's a mean little detail in the PDF/X spec that says the output intent must use an "Output Device Profile" which sRGB isn't (It's a Display Profile). Since all Output Device Profiles I found so far are CMYK profiles I obviously need to look into this a little. What I'm planning is to properly map XSL-FO's sRGB values into proper sRGB color values in the PDF (by mapping DefaultRGB into sRGB). That way I can avoid converting colors early and still indirectly set up the color transformation from sRGB to the target CMYK profile.
What I'd like to know is whether you've already done some work in the CMYK area. Not that we duplicate our efforts. Jeremias Maerki