All Xara documents, either created by you from blank or a pre-designed template, are built to work together. It's a powerful benefit of the Xara platform in that every document is fully compatible with each other.
To copy pages from one document to another, you first need to open both of them in separate tabs. (how-to video below)
Open the document you wish to copy pages to.
Go to File > Open in new tab and select the document you wish to open pages from
In the page view on the left, select the page you wish to copy and press Ctrl + C or Cmd + C
Go back to the document you wish to paste to, select a page within the page view again and press Ctrl + V or Cmd + V. The page will then be copied under the selected page
Do this for every page you wish to copy over.
When you paste in a page, the newly pasted page will inherit the theme colours of the document you are in.