Track changes in Excel

Hello,

I want to write a macro which track changes in the worksheet. Suppose the value in the cell has been changed, then it will mark the cell as yellow in color. But if after making a change it reverts back to the same value as previous, then the cell will again become white in color. For tracking changes I want to compare sheet1 and sheet2. Note that in sheet2 user may insert or delete rows, which i need to take care while comparing.

Kindly help