I am using writer 6.3.5.2 with Ole spreadsheets embedded. If the cells in the spreadsheet have black borders, the spreadsheet appears completely black in the writer document when i exit the calc doc. if I use other colors for the cell borders and return to the writer document, the embedded spread sheet is the color of the cell borders but now the cell contents are visible. The cell borders are set to 0.05 pt. When the write window zoom is changed sometimes the OLE calc cell contents appear normal. Is there a work around for this problem? I did not have this issue in my previous version of LO. I am using OSX 10.11.6 I can attach screen grabs if that helps in understanding the problem.
If set, try to disable OpenGL in LibreOffice -> Preferences -> LibreOffice -> View -> Category: Graphics Output -> Option: [ ] Use OpenGL for all rendering and check whether that fixes your problem