Wasn't sure where to post this question, so I thought I would start here.

The question is to do with Illustrator and Xara.

If I create a document in Xara, and then export that as a PDF, then a lot of the colours colours do not export as well as they should do.
However, if I create a document in Illustrator, then the colour are very similar, if not identical when saved as a PDF.

So, why doesn't Xara manage this as well as Illustrator?
What is it that Illustrator has, to be able to save the document much, much better?