ImageColorSpaceExportMode

public PdfImageColorSpaceExportMode ImageColorSpaceExportMode { get; set; }

Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

builder.Writeln("Jpeg image:");
builder.InsertImage(ImageDir + "Logo.jpg");
builder.InsertParagraph();
builder.Writeln("Png image:");
builder.InsertImage(ImageDir + "Transparent background logo.png");

// Create a "PdfSaveOptions" object that we can pass to the document's "Save" method
// to modify how that method converts the document to .PDF.
PdfSaveOptions pdfSaveOptions = new PdfSaveOptions();

// Set the "ImageColorSpaceExportMode" property to "PdfImageColorSpaceExportMode.Auto" to get Aspose.Words to
// automatically select the color space for images in the document that it converts to PDF.
// In most cases, the color space will be RGB.
// Set the "ImageColorSpaceExportMode" property to "PdfImageColorSpaceExportMode.SimpleCmyk"
// to use the CMYK color space for all images in the saved PDF.
// Aspose.Words will also apply Flate compression to all images and ignore the "ImageCompression" property's value.
pdfSaveOptions.ImageColorSpaceExportMode = pdfImageColorSpaceExportMode;

doc.Save(ArtifactsDir + "PdfSaveOptions.ImageColorSpaceExportMode.pdf", pdfSaveOptions);