Excel 2003 SP3

I'd like to set the background cell color based upon the concurrent values
of two (2) cells.
Let's say that Column A has the day of the week and Column D and Column E
have various calculated values based upon the data in Column C (measured
data).
So, if cell D10 has a calculated value of "B" AND cell E10 has a calculated
value of "B" then I'd like for A10 (day of week) to be filled with a
background color of, say, green.
However, if cell D10 has a calculated value of "S" AND cell E10 has a
calculated value of "S" then I'd like for A10 (day of week) to be filled with
a background color of, say, red.
All other combinations would leave the background color of cell A10 as-is
(standard white).
How can I do this as the Conditional Formatting doesn't work since this is
referencing other (external) cells.
TIA!