YOU ARE THE MAN!
Thank you!
In the theme /css/core file I edited the default.php and uploaded it with cache disabled and boom.. it worked!
I think I understand how this works now :)

Before doing any changes on the server Ossn cache MUST be DISABLED from your admin backend

I had actually found it with the inspector and could temporarily change it in the inspector to make sure.
The place where I changed it was in the cache though.. a file called ossn.default.css which didn't change anything when I uploaded it there:

The code must be somewhere else because if the cache is cleared that reverts back to the default or?

Well,
rather than guessing, it's clicking the part of interest and looking into the developer console

Hence, if you want to change the color of the 2 paragraphs inside ossn-site-pages-body to white
you have to address them like

.ossn-site-pages-body p {
   color: white
}

But why choosing this complicated way at all when we have a comfortable editor which allows styling changes like that from its toolbar?

I am guessing I would have to change the "col-md-12 ossn-site-pages-inner ossn-page-contents" color

OK.. thank you.. I saw that but was not aware of what to search for, I thought someone could give me some tips.
I know basic html, a little css but am mostly a .net programmer.

Bob,
first, there's a How-to which way to find something in the source on
https://www.opensource-socialnetwork.org/wiki/all?offset=2

next, I recommend to report non standard theme/component related issues directly below the affected theme or component. This way the developer will receive a notification automatically.

This is a snapshot of the Terms and Conditions page. Where the text is, I would like to make that white.