When an Excel spreadsheet is opened on the screen, none of the color or line
formats are showing up. When you select print preview to print however, all
of the formatting is on the worksheet.

Bottom line...no colors are showing nor can any be added. For example, if I
open a workbook that was created on another computer, not one color is
showing except on printed copies.

How can I restore the ability to format the colors on the worksheet???