As most people are aware, there are red and green flashing lights inside the dome on the front of the meter. You know this minature Christmas trees they make for cars? You could try find one that has only green and red lights and you can secure them inside a dark coloured/tinted plastic cover. You might have to see if they make a set that flashes or not. If not then you might have to buy a LED set from your local hardware or electric store. In the Uk I can suggest Tandy's if it's still there or Halfords. But for those in the US, you'll just have to go to whatever shops you know.