Revindex themes are highly configurable. You can customize many aspects of the theme such as font, color, background, etc. To change the settings, simply edit the page and click on the gear icon.
Please note, the settings are per layout. For example, if you're using the "home" layout for Home page and "inner" layout for the internal pages, you should change the settings on both layout's settings. Simply edit the Home page and modify the theme settings. Repeat the same step by going to any one of the internal pages and modify its theme settings.