MOO's printers use a 4 colour ink process (CMYK). Please be aware that screen colours (RGB) may appear duller or lacking in contrast when printed.
Always preview your work in CMYK where possible.
We use public ICC profiles, so if you preview and save your files using the 'Coated FOGRA39' colourspace, they will not be altered by our back end processes.
To set the correct colour space for your PDF, click on the 'output' option shown on the left of your screen when you select the 'Adobe PDF/X-1a:2001' preset. In the 'colour' box, select 'Coated FOGRA39' from the destination dropdown.
Please note, we don't offer any spot colour or any pantone matching, so its best to remove them from your PDFs and ensure only CMYK colour values
This video explains the difference between RGB and CMYK.