Hello,
This is not connected to the color space name. In this case, the color space is declared as an external resource which is a separate issue and is logged as well: https://feedback.telerik.com/document-processing/1406597-pdfprocessing-notsupportedcolorspaceexception-is-thrown-when-importing-color-space-defined-as-an-external-resource.
Regards, Dimitar Progress Telerik