   for(uint8_t x=0; x<COLS; ++x){
     //first row -> turn off the off pixels after propagation of colour
     if(!onPixels[0][x]){
-      new_colors[xy2i(x,0)] = CRGB::Black;
+      new_colors[xy2i(x,0)].setHSV(0,0,0);
     }
   }
 }

        new_colors[xy2i(x,y)] = new_colors[xy2i(x,y-1)];
      } else {
        // If off, turn the pixel off (the actual pixel colour has a FO low-pass filter)
        new_colors[xy2i(x,y)] = CRGB::Black;
      }
    }
  

#define NUM_LEDS (ROWS*COLS)

CRGB leds[NUM_LEDS];
// Keep the current colour available in HSV
CHSV colors[NUM_LEDS];
CHSV new_colors[NUM_LEDS];


#define LOOP_TIME 20
