Conditional Formatting across Multiple Sheets

Hi,

Just wondering if it is possible to Conditionally Format across multiple worksheets.

By that what i mean is i have at least 4 to 5 work sheets in each workbook and these cells contain mobile phone numbers.

Across the sheets one or two numbers will appear multiple times and I can manually set the conditions for them but as the workbooks expands i would like the workbook to do it automatically ie via a macro if possible.

Wat i would like to be able to do is highlight the number is red or any colour.

Just wondering is this possible.

Thanks

Alan