According to the Publisher help, colors within a Publisher document are defined by the color space of the document, and all pictures (and other elements) imported to the document are instantly converted to this pre-defined document color space. When I e.g. create a new document and choose "RGB/8" as the color format and "sRGB" as the color profile, then all imported pictures, text colors etc. are converted to the sRGB color space in 8 Bit color depth. But there is no way of checking if this really happens; I need to trust the software to do it correctly.
Whenever I want to change colors of already existing vector/text elements I would expect to see the color selector only for the color format the document is defined in (like RGB sliders für RGB or CMYK sliders for CMYK). But I can still choose betweens different color selectors and e.g. define a text color within a RGB document using the CMYK sliders. That doesn't make much sense to me - especially for texts and b&w vector graphic elements.
When I'm editing an RGB document and am inserting some running text in black, I'm tempted to just use the CMYK sliders and the color value 0/0/0/100 (i.e. only black ink - like it is standard for runnig text in CMYK printing documents). But when I switch to RGB just to check, I see that I unwillingly have created text with RGB color values 35/31/32. On a screen this would only be a dark gray instead of full black, an RGB printer driver would print it with mixed colors (instead of black only).
And there is an even bigger problem the other way round, i.e. when I'm editing a CMYK document and choosing the color with RGB sliders: From RGB values 0/0/0 (standard for black text in RGB documents) I get the CMYK values 62/67/68/88. If I send the exported PDF with this value to my print office, I get unsharp text with a strange mix of 4 rasterized colors (instead of sharp black-only print).
I tried one other thing: I exported a pdf file from my text editor (TextMaker in my case - but it would be the same with any other office software) and imported it into Publisher for further editing. Office programs tend to give out everything in RGB colors, so the black texts in this document are defined as RGB value 0/0/0. When I choose CMYK format for input, Publisher converts all the text color to CMYK value 62/67/68/88, i.e. the same unusable color mix as described above. The same thing happens when I stay in the RGB format while editing and only choose CMYK for export. My only chance to get it right is to manually change all the black text frames to CMYK value 0/0/0/100 before I export; in complex and long documents this can be a lot of work. (I didn't find any option to choose how the black color of text elements should be interpreted during import.)
It seems to me like the developers of Affinity Publisher believed that you can convert RGB and CMYK colors any time and in any direction and that wouldn't make much difference at the end, but that is not the case. Especially the Black in CMYK format can be mixed very differently depending on the purpose (e.g. black-only for small text and fine lines, mixed colors for bold headline text and graphic elements).
If you want to export pdf files in CMYK colors for professional offset printing, you need full control over the CMYK values at any time. I don't see this in Pubisher at the moment. Is it just me or are other users having the same problems?
