float r=0;  //initialize float variable "r" to 0
float g=0;  //initialize float variable "g" to 0
float b=0;  //initialize float variable "b" to 0

void setup(){
size(400,400);  //set canvas size to 400x400
frameRate(30);  //set frame rate to 30 frames per second
background(0);  //set background color to black
}

void draw(){
  noStroke();  //remove borders on shapes
  fill(0+r,0+g,0+b);  //fill color for ellipse
ellipse(mouseX,mouseY,50,50);  // draw ellipse at mouse location
  r=random(0,255);  //set r variable to get random number between 0 and 255
  g=random(0,255);  //set g variable to get random number between 0 and 255
  b=random(0,255);  //set b variable to get random number between 0 and 255
}

void mousePressed(){
  fill(random(0,255),random(0,255),random(0,255)); //give rectangle random fill color
  rect(random(0,400),random(0,400),100,100); //draw rectangle on mouse click
}