Hi there,
Simple (when you know how!!).
1. Right click the field you want to highlight and select Format Field
2. Go to the Border tab
3. Click the x2 button to the right of the Background property. This opens the Formula Editor. You have to create the expression for which you want the property to be used
4. Build
If {Despatch Date Field} > {Due Date Field} Then
crYellow
Else
crNoColor
Notes:
1. You can use whatever colour you want instead of crYellow, but it has to be a Crystal reports constant. If you want non-regular colours, you can use the Color function, which takes three arguments all between 0 and 255. This determines the Red, Green, Blue factors in the colour
2. You must stipulate crNoColor in the Else part - otherwise everything goes black - that's the default colour in an expression like this.
Good luck!