@Override
    public ArrayList<Delta> apply(Color c, int x, int y, Color[][] colorArr) {
        ArrayList<Delta> d = new ArrayList<>();
        if (x < colorArr.length && x >= 0 && y < colorArr[x].length && y >= 0) {
            d.add(new Delta(x,y,colorArr[x][y],c));
            colorArr[x][y] = c;
        }
        return d;
    }