option 1:

To do it manually, press the F5 key to bring up the GoTo dialog. Click the Special Cells button. On the next screen, select Formulas (it's an option on the right).

Excel will select all of the cells that match. Now it's just a matter of applying formatting.

option 2:

Excel has a built in feature of "Trace Dependents" (which shows arrows to show you the calculated cells)

Select the range containing your data.
Excel 2007 - Formulas - Trace Dependents

all the best