Colleagues

I'm getting ready to send  a book to the  printers and in their blurb they state "Ensure that you are using a CMYK workflow and export to PDF/X-1a:2001" . I can set the pdf format using \setupbackend but I'm unsure as to what to do about CMYK workflow. The book has no colour pages so I'm not sure if I really need to worry about CMYK workflow. Could someone advise?

Thanks and Best Wishes

Keith McKay