Yes, that is right. But I wonder if there is a license of using the same theme or installation package for the website because if I see on the other materials, each people who buy the license will have the same materials.
The structure of the website (the HTML code) is not subject to copyright, you can open
www.google.com and simply copy their page.
But the content of the page (i.e. pictures), is different, they are copy protected. So as long as someone copies Bustadice, changes colors, content and pictures, it's legally okay.
Of course, it is very confusing for the user of the site if pages are too similar. He immediately gets the impression that they are interdependent and come from the same operating team - or worse, that one page was copied from the other and could be a scam. In the worst case, this can even deter users.
For the sake of completeness here is a statement of a lawyer (translated from German):
The HTML coding created by you is not protected as work in the copyright sense. This is due to the fact that, according to unanimous case law, HTML does not contain an executable sequence of individual instructions, but only serves to make the formatting of the page and the positioning of graphics visible on the Internet.
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