size(400, 400);
background(213,132,255);
stroke(255, 201, 3);
smooth();
rectMode(CENTER);

int shapeSize = 400;
int kindOfShape = 0;

while(shapeSize > 10){

if(kindOfShape == 0){

fill(213, 132, 255);
ellipse(200,200,shapeSize,shapeSize);
ellipse(200,200,shapeSize-10,shapeSize-10);
kindOfShape = 1;

}else{

fill(54, 45, 56);
rect(200,200,shapeSize+7,shapeSize+7);
rect(200,200,shapeSize,shapeSize);
kindOfShape = 0;

}

shapeSize = shapeSize - 20;

}