The H5P plugin for WordPress received proper support for theming in version 1.17.4. However, H5P Group decided to keep the theme picker that allows you to set a global theme for all H5P content types an exclusive feature of H5P.com. This plugin fills that void and gives you the same options.
Install
Install from the WordPress plugin repository and activate.
Configure
You will find a new settings menu item labeled “H5P Themer”. It allows you to pick from a list of predefined themes or define your own custom theme. You can also choose the density, which influences how wide or compact H5P content will appear.