Array example in P5, make an array of colors and draw a rainbow. Includes how to append and splice in elements

rainbowArray.js

var rainbow; //global variable

function setup() {

  createCanvas(600, 600);
  
  //make the list (array) of rainbow colors
  rainbow = [color('#c0392b'), color('#e67e22'), color('#f1c40f'), color('#2ecc71'), color('#3498db'), color('#8e44ad')];
  //shift to the center and down a bit
  translate(width / 2, height / 3);

  //draw the rainbow!
  drawTheRainbow();

  //woops we forgot to include indigo! Let's splice it in
  //let's retrieve red
  var blue = rainbow[4];
  //and violet
  var violet = rainbow[5];
  
  //halfway between blue and violet
  var indigo = lerpColor(blue, violet, 0.5);
  
  //splice arguments are where to splice, how many to delete, item to splice in
  rainbow.splice(5, 0, indigo);

  //draw the rainbow again!
  translate(0, height / 3);
  drawTheRainbow();
}

function drawTheRainbow() {
  strokeWeight(10);
  for (var i = 0; i < rainbow.length; i++) {
    stroke(rainbow[i]);
    arc(0, 0, 300 - i * 30, 250 - i * 30, PI, TWO_PI);
  }
}

function draw() {

}