Arc Chord. Using p5.js library.

arc-chord.js

function setup () {
  createCanvas(896, 504);
}

function draw () {
  background('#ed225d');
  noStroke();
  for (i = 0; i < 6000; i++) {
    fill(random(255), random(0, 170), random(255), 150);
    // negative x-axis values help arc chords fill entire canvas
    arc(random(-250, 896), random(-150, 504), 400, 400, random(QUARTER_PI), QUARTER_PI, CHORD);
  }
frameRate(10);
}