int circleSize = 1;
int mrRed = 0;
int mrGreen = 0;
int mrBlue = 0;
float mrRandom = 0;
int circleMax = 500;

void setup(){

size(400, 400);
background(0);
stroke(100,50,255);
strokeWeight(1);
noFill();
smooth();

}

void mouseDragged() {

mrRandom = random(0,255);
mrRed = int(mrRandom);

mrRandom = random(0,255);
mrGreen = int(mrRandom);

mrRandom = random(0,255);
mrBlue = int(mrRandom);

mrRandom = random(10,500);
circleMax = int(mrRandom);

stroke(mrRed,mrGreen,mrBlue);

while(circleSize < circleMax){
 rectMode(CENTER);
rect(mouseX,mouseY,circleSize,circleSize);
circleSize = circleSize + 3;

}
circleSize = 1;

}

void draw(){

fill(10,10,10,10);
rect(0,0,400,400);

}