function

void setup(){

  size(500,500);

  background(#90B5CB);

  noStroke();

}

​

void draw(){

  for(int i=25; i<width;i=i+50){

    for(int j=25;j<height;j=j+50){

      pattern(i,j);

    }}

  }

  void pattern(int x, int y){

    rectMode(CENTER);

    fill(#508DEA);

    rect(x,y,50,50);

    fill(#89A9DB);

    rect(x,y,40,40);

    fill(#EFD3F0);

    rect(x,y,20,20);  

    fill(#94C8F5);

    rect(x,y,10,10);

    stroke(#7B137C);

    stroke(#6154F5);

    line(x-50,y-50,x+50,y+50);

    stroke(#C17FC1);

    line(x-25,y+25,x+25,y-25);

    stroke(#C17FC1);

    stroke(#3525F5);

    line(x+25,y,x-25,y);

    line(x,y+25,x,y-25);

  }