For each PDF/A-1 validation issue we try to explain what it means and, if possible how to resolve it. For a more technical explanation of the issue we quote the related section of the ISO 19005-1 PDF/A Specification.
PDF/A requires device specific colour space parameters to insure that the document will render and output as close to the original colors as possible.
The document does not specify any colour space, specifies multiple colour spaces or the colour space in use is not correctly identified.
How can I fix it?
Use a PDF creation product that correctly identifies colour space. We recommend Solid PDF Creator Plus.
If you are working with a legacy document, simply open your PDF file in Solid PDF Tools and then File | Save As PDF/A. This will add or adjust the colour space used in your PDF/A file.
6.2.3.3 - ISO 19005-1 PDF/A Specification:
A conforming file may use either the DeviceRGB or DeviceCMYK colour space but shall not use both. If an uncalibrated colour space is used in a file then that file shall contain a PDF/A-1 OutputIntent, as defined in 6.2.2. DeviceRGB may be used only if the file has a PDF/A-1 OutputIntent that uses an RGB colour space. DeviceCMYK may be used only if the file has a PDF/A-1 OutputIntent that uses a CMYK colour space.
When rendering a DeviceGray colour specification in a file whose OutputIntent is an RGB profile, a conforming reader shall convert the DeviceGray colour specification to RGB by the method described in PDF Reference 6.2.1.
When rendering a DeviceGray colour specification in a file whose OutputIntent is a CMYK profile, a conforming reader shall convert the DeviceGray colour specification to DeviceCMYK by the method described in PDF Reference 6.2.2.
When rendering colours specified in a device-dependent colour space a conforming reader shall use the file’s PDF/A-1 OutputIntent dictionary, as defined in 6.2.2, as the source colour space.