I wish to format a cell so that the background colour varies according to the following criteria:
Colour 1: if the cell content contains a formula that refers to another worksheet within the workbook
Colour 2: otherwise (NB it will never refer to another workbook, so no need to cater for that)

It may require a VBA solution in the worksheet module. I would be content with that if necessary. If there is a non VBA solution that would be preferred.

It needs to be compatible with Excel version 2003 but I doubt that that will be an issue.

Any help would be appreciated.