How to reset color palette
 

I open Excel and have the default palette and then realise later on that a
mystery file I have opened has changed the palette. In the meantime I have
saved all the files I have open.

My question is how do I restore the original palette?

I try tools/options/clour/reset - doesn't work. I try closing Excel and
reopening the file - doesn't work. I try copying a palette from another
workbook - doesn't work b/c when I open an untainted workbook, it's palette
is converted from the default to the unwanted palette.

I'm at a loss - please help