CMYK Color Settings in Illustrator 2026

Dear all

I will have numerous graphical illustrations (around 500 diagrams/illustrations) printed on uncoated paper using the Indigo printing process. Since the entire print job is very expensive and complex, I would like to ask you for urgently needed advice on how to correctly set my color settings. I am working in CMYK and will print the illustrations in Switzerland / Europe. 

• Is there a good tutorial / article that differences in the various color settings like “Adobe Illustrator 6.0 Emulate” / “CMYK Coated FOGRA 39 / Europe General Purpose 3 / etc.? 
• What happens if I change this color settings in a while? Do my colors get distorted by changing the color settings or how does it affect my illustrations?
• I am planning to work with Adobe Illustrator 6.0 Emulate. Can you recommend this setting? Can you please explain what this profile does compared to the other color profiles?
• Why is it that important to choose the right settings right from the start?
• Which CMYK color values should be used to achieve the deepest possible black?
  Can I work with C 50% / M 40% / Y 40% / K 100% or which setting do you recommend?
• Which settings should I use to export the PDF for printing? I am planning to work with PDFX-4, can you recommend that?

Thanks a lot for your appreciated support!

Best regards, Silvan