As the online office app is built on a CMS as most of websites in the internet, it use a concept of 'theme' or visual template.
Theme consists of a set of templates, while each template describes layout and styles. Each page is rendered basing on chosen template.
According to this concept it's possible to create any new theme for the online office app to make it look whatever you want. This however is a custom development so it can be done either by MLM Soft engineers, or any official integrated in your region, or even by your engineers in-house.
Theme is a set of twig format files which is widely used to markup webpage layout.
You can get more information about this format and how to create custom themes using it here.