Conditional formatting in Excel 2007 (and later) allows us to colour cells on a spreadsheet depending on whether or not they meet certain conditions. While it existed to some degree in Excel 2003, it has been seriously beefed up in Excel 2007 and later.
This particular tutorial was born from a request on a Facebook group. One of the users asked me how they would format a list of names and addresses to change colour depending on date of last contact. I thought this would make an interesting tutorial and here it is.