Use Format-Conditional formatting
In addition to the answer you recieved above,
Step 1 Click FORMAT
Step 2 Click CONDITIONAL FORMATTING
Step 3 In the box that appears select CELL VALUE IS in the next reference area select EQUAL TO. in the third reference area Type the reference you wish in quotation marks ie "X" then click FORMAT this box that appears there allows you to select font styles and COLOUR etc as well you can add two more Conditions by clicking add and going through step 3 again.
I have just figured this out myself not one hour ago, how is that for timing
Best of luck
mikcassidy@mikesmail.com