function setup() {
createCanvas(200, 200);//x, y
background(0, 30, 0);//rgb values, go from 1 to 255, 000 is darkest color, 4th is alpha (opacity)
}
function draw() {
background(0, 30, 0); //makes it so that the background covers circles so there's no trail
fill(255, 200, 200); //fill of circle
stroke(0, 255, 20); //stroke of circle
ellipse(mouseX, mouseY, 50, 50);
}