IF you have certain data in cell that needs to be highlighted and brought attention to, merely changing its font attributes may not always serve the purpose. You can try some simple macros to make your cell contents flash instead. First you need to define a cell style. To do so, carry out the following steps:

~ Go to the 'Home' tab.
~ Click the 'Cell Styles' option appearing under the 'Styles' group. ~ Click the 'New Cell Style' button appearing at the ~ase of the drop-down list.
~ Set the 'Style Name:' value as 'flashing', and set the attribute values as required.
~ Click 'OK' to create the cell style.
~ Next, select the cells to which the cell style is to be applied.
~ Click the 'Cell Styles' option appearing under the 'Styles' group of the 'Home' tab.
~ Select the newly created 'flashing'
style.
~ Next, go to the 'Developer' tab. NOTE: If you cannot find this tab, click the 'Office' button, click the 'Excel Options' button and check the 'Show Developer tab in the Ribbon' option.
~ Click the 'Visual Basic' option under the 'Code' group of the tab.
~ Right-click on the 'Module' component in the 'Visual Basic' editor window.
~ Select 'Insert I Module' from the context menu.
~ In the module window, type the two following macros.

Code:
Dim NextTime As Date

Sub StartFlash () NextTime = Now + TimeValue (' 00: 00 :01') With ActiveWorkbook. Styles (' Flashing') .Font If .ColorIndex = xlAutomatic Then .ColorIndex 3 .ColorIndex = 5 -.ColorIndex 
End With 
Application.OnTime NextTimer 'StartFlash' 
End Sub 

Sub StopFlash () Application.OnTime NextTimer 'StartFlash', schedule:=False ActiveWorkbook. 
Styles ('Flashing') . Font. ColorIndex = xlAutomatic End Sub
~ To start the effect, click the 'Macro' ,option under the 'Code' group of 'the tab.
~ Select 'StartFla;sh' and click 'Run'.

The contents will appear in red and white color in a'span of one second each.

~ To stop the effect, Select 'StopFlash' and click 'Run'.