Conditinal Formatting

For a certain column, there are 3 options that can happen
1. "PAID"
2. "UNDERPAID BY ..." (... is a variable number)
3. "OVERPAID BY ..." (... is a variable number)

I am trying to use conditional formatting to make "PAID" in a green box, "UNDERPAID BY..." in a red box and "OVERPAID BY..." in any colur box.

The problem is with the "UNDERPAID BY ..." and "OVERPAID BY...." as they are variables.
Is there any way around this?