I would recommend a Conditional Format

Select the cells you want to colour
Selet Format | Conditional Formatting...
Cell value is | Equal to | =""
Select Format and choose a blue background.
OK
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HTH...

Jim Thomlinson


"OldPoplarPete" wrote:

I want to automatically change the colour of a cell in Excel when data is
added to that cell. For example: an empty cell has a blue backcolor when a
number is put into the cell the background automatically changes to white.