Yep, do it all the time with fmp 10.
In layout mode, right-click the field and choose conditional formatting.
Click the Add button and choose "Formula Is" instead of "value is."
Click the specify... button and enter a calculation that evaluates to true or false such as:
table::Adifferentfield = "Stop"
Then choose the formatting you want for that condition.
For more about conditional formatting, look it up in the help system.