Where to insert the break; line in my code?

      if(c == 'o')
         off = true;
   }

   if(off)
   {
      OFF();
   }

Once you've turned the strip off, does off still need to be true? What happens if you set off to false after turning the LEDs off?

If course, it will look silly having off false to mean that the LEDs should be off. A better name is DEFINITELY in order. Something like needToTurnStripOff is much better than off.