In Excel 2007 on the HOME tab click on Conditional Formatting, click new rule, select Format only cells that contain, in the section called edit the rule description, go to the 2nd dropdown box click on the and select Greater than or equals to, go to the 3rd dropdown box and enter condition =A1, then click on the Format button, click on Font tab, click on dropdown box under color select the color you want click OK as many times as need to exit.