customisation not working

I have bought the pro version to be able to customise the colours and background of my website yet it is not working.

Choosing a different colour for headings, putting texture or background image, etc. I try them and save my choices but nothing changes on the website itself(the preview does not work most of the time as well).I cleared my browser cache and it did not work either. I checked and my changes are saved as I can find them if I go back to the customise page but they are not applied to the site.

any idea what the problem might be?