void setup(){

  size(500,400);

  fill(255,0,0);

  rect(0,0,50,50);

  fill(0,255,0);

  rect(0,50,50,50);

  fill(255,255,255);

  rect(0,100,50,50);

  rect(0,150,50,50);

  rect(450,0,50,50);

  rect(450,50,50,50);

}

int www=5;

void draw(){

  if(mousePressed && mouseX<50 && mouseY<50) stroke(255,0,0);

  else if(mousePressed && mouseX<50 && mouseY<100) stroke(0,255,0);

  else if(mousePressed && mouseX<50 && mouseY<200) save("aaaa.png");

  else if(mousePressed && mouseX<50 && mouseY<250){ 

    PImage file = loadImage("aaaa.png");

    image(file, 0,0,500,400);

  

  }else if(mousePressed && mouseX&rt;450 && mouseY<50){

    strokeWeight(++www);

  }

  else if(mousePressed && mouseX&rt;450 && mouseY<1000){

    strokeWeight(--www);

    if(www<2)www=2;

  }

  else if(mousePressed)  line(mouseX, mouseY, pmouseX, pmouseY);

}