public void updateDisplay() {
		if(userPaint!=null && systemPaint!=null) {
			for(int row = 0; row<systemPaint.length; row++)
				for(int col=0; col<systemPaint[row].length; col++) {
					systemPaint[row][col] = toColor(userPaint[row][col]);
				}
		}
		super.repaint();
	}