One caveat, however . . . use of the form's timer system produces a "power sapping application (at least those are my rememberances before I banned the use of the timer system from all my applications, except very, very special circumstance).
Set the TimerInterval for the form to whatever millisecond flash rate you want.
Add code to your OnTimer event to alter the background color of the field in question.
If [Field] < 10 then
If [Field].BackgroundColor=00000000 then
You may want to further define the process by not setting the TimerInterval until a certain condition exists. That way the timer isn't running all the time.