Pages as tabs with the active tab colored differently?

A number of themes do that so take a look at how this theme uses tabs for both Pages and Categories:
https://www.ads-software.com/extend/themes/amazing-grace

Also review:
https://codex.www.ads-software.com/Template_Tags/wp_list_pages#Markup_and_styling_of_page_items

Thanks, but I think we cannot use it that way. Our page navigation consists of images with a non-standard font used. So I guess we have to hard-code the pages like that:

<a href="page01">
     <img src="page01button.gif" />
</a>
<a href="page02">
     <img src="page02button.gif" />
</a>

etc.

But how can we get the correct link to a page? Is there something like <?php get_page_link($pageId); ?>

See get_permalink.