I am currently using Excel 2007 and have a large workbook. When I go to make a format change in any of the tabs, the colors across the workbook change to some base color pallette. I'm not making coloring formatting changes, just formatting changes in general, such as adding a border around a group of merged cells.

Not only do the colors change, but some of the formats (such as the border) seem to change too. For example, in a group of merged cells with a border around it, the uper right hand portion of the border will disappear.

Please help.