Here's exactly what I mean by that. Let's say I pulled a Microsoft Office docx file off the Web. I know I can easily open it up in LibreOffice and make changes to it. I'm also able to save it. If I take that file now and try to open it in Microsoft Office, will I see all my changes that I made to it in LibreOffice without MIcrosoft Office complaining?
Yes, it is possible : DOCX is handled by LibreOffice.
Meanwhile, some formatting functions are not compatible between both "offices". Sometimes, some colors applied will not being seen in each other.
Yes, and no.
Yes, LibreOffice and MS Office both support the docx format.
However, LibreOffice and MS Office are not necessarily using the same fonts, so documents may look different as a result. LibreOffice also doesn't necessarily handle all the things that may be embedded in the document, nor any macros, so opening in LO and then saving back out, may lose some data which cannot be handled.
Saving as .docx in LibreOffice might work, but I often find problems. Instead, there are two more reliable methods on Linux: