Excel changes colors inexplicably
If when you copy data from one Excel spreadsheet to another, you notice that the cell colors inexplicably change from one shade to another, the problem may come from the fact that one of the workbooks has a different theme selected.
Under Page Layout, check to see which Theme is selected in the drop down menu.
Under Options, in the Save section, you can get the color theme from another workbook by clicking on Colors in the 'Preserve visual appearance of the workbook' section.
Select the open workbook whose color scheme you want to replicate.