At Drupa CGS has shown their ORIS CxF Toolbox and the CxF Designer. They allow the use of spot colors with spectral color definitions according to the new standard CxF/X-4 (ISO 17972-4:2015) in PDF/X files.
CxF Toolbox converts measuring data from any instrument to CxF data and embed them in a PDF/X file. With the CxF Designer CxF files can be imported into the swatch library of Adobe CC applications. During export the CxF data is automatically embedded into the PDF/X file.