Hi
this can be done without any code using conditional formatting
select the cell(s)
choose format / conditional formatting
choose
cell value is
choose
equal to
in the white line type
0
click on the format button go to the patterns tab choose the red
click Ok
click ADD
repeat the steps as above using the new criteria and colour
click ok twice.
If you'ld prefer a code solution, please feel free to post back
Cheers
JulieD