Represents the "ProfileCS" entry of the destoutputprofileref dictionary object.

It is defined as part of the PDF 1.0 specification.

It contains a string representing a PDF string object.

For definitive details see:.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 402, page 817.

The ProfileCS entry names the color space of the ICC profile input, such as CMYK, RGB, or Gray. This allows processors to identify the profile type without parsing the profile data stream.