Code Sketch

// Clear the canvas and set background
clear()
invisible()
setAnimationDelay(0)
setBackground(black)

// Use a 'for' loop so 'i' is defined:
var radius = 2.0
var angle = 0.0

for (i <- 0 until 300) {
  val r = (100 + i % 155).toInt
  val g = (50 + (i * 2) % 205).toInt
  val b = 255
  
  setPenColor(Color(r, g, b))
  setPenThickness(1 + (i % 3))
  
  forward(radius)
  right(90)
  forward(2)
  
  setPosition(0, 0)
  
  angle += 12
  setHeading(angle)
  radius += 0.8
}