Extensions are the perfect way to tailor a DokuWiki installation to suit your needs..
Templates (a.k.a. themes)
By installing new templates you can change the look and feel of your site. For most templates the color scheme can also be easily adjusted by editing the template's style.ini file. Information about how to create your own personal template is also available in the development manual. Build it faster by starting from the Starter template.
Plugins are able to change behavior and add additional syntax in your installation, for example, adding support for columns, issue trackers or replacing the editor with a WYSIWYG one. If you can't find a suitable plugin you can write your own or add it to the plugin wish list. Information about how to create a new plugin is available in the development manual.