I wanted to color a cell in Excel 2010.  I selected the cell and clicked on the icon that fills but nothing happened.  I then opened the format cells dialogue and selected background color.  Still nothing.  I checked permissions and saw it was protected once and locked once (different times  and different attempts).  I unchecked those and tried again. Nope.  I then went to conditional format and cleared any rules.

Nothing I do makes the cells have color.  I'm running into the same problem with LibreOffice. 

I've never had any trouble in the past with other versions of Excel.  This is on my Windows 7 machine with Excel 2010 and LibreOffice Calc 6.0.2.01