for (int i = 0; i<lightCount;i++){
    if ( i == vol) {
        strip.setPixelColor(i, strip.Color(255,0,0));
    else if (i < vol){
        strip.setPixelColor(i, strip.Color(0,255,0));
    }
    else if (i > vol) {
        strip.setPixelColor(i, strip.Color(0,0,255));
    }
  }