Summary:
The PDF exported from the QuarkXPress shows different colors when viewed in iOS devices
PDF exported from QuarkXPress PDF when viewed on iOS devices


Solution:

1. Open the document in QuarkXPress.
2. Navigate to File> Export> Layout as PDF.
3. Click on Options and choose Color in the left pane.
4. In the setup, choose ‘Composite RGB’ and then Export the PDF.
5. Now, the PDF colors will appear fine on iOS devices.