Opencast customization

i'm using Opencast to develop a video web portal.

I'm new to using Opencast and finally after one day i installed it on my machine and it runs correctly.

I installed it on Ubuntu 18.10 by following the "Installation from source" guide on the official OpenCast website.

Now i'd like to know how this application could be customized.

I need to change the logo and colors on the home page for users. I cannot see any html or css files to edit.

Thanks you in advance