Hi Everyone,
I am using Excel 2010. Periodically, I experience an issue where the standard colors in Excel's color palette will change, and subsequently, any file that I open which uses one of the affected standard colors, will appear different. I am almost certain that the behavior occurs after opening emailed files coming from another company, and/or copying and pasting from those files into my files. It seems inconsistent and I haven't been able to narrow down exactly what file or action is causing the issue. Once it appears, it affects every file that I open. The only fix I have found is to open a new instance of Excel, or completely close the affected instance and reopen Excel. Both of those will reset the standard colors and my files appear normal again, however, this is a pain when you have a dozen or more large files open and need to close out of every one and reopen just to get the colors back to normal. I've been dealing with this for years and have begun looking into it more. I've seen similar issues described in the forums, but none with a solution that has worked. It happened again today, so I grabbed some screenshots.

Here is a screenshot showing the standard colors after the issue occurred:
Messed up colors.jpg

I opened a second instance of Excel and took this screenshot of my normal Excel colors.
Normal colors.jpg

You can see that a few colors changed or shifted places, and those are the same changes I am seeing in my files (ex: cells using the standard blue font color all turn to ivory when the issue strikes)... until I close Excel completely or open a new instance. Does anyone know what is causing this, or a way to reset the colors easily without closing Excel or changing them one-by-one?