clear()
setSpeed(fast) // speed up the turtle
setPenColor(cm.black)
setBackground(Color(0, 102, 102))
var clr = cm.rgba(255, 0, 0, 150) // start with a semi transparent red color
repeat(51) {
setFillColor(clr)
repeat(4) {
forward(100)
right(90)
}
clr = clr.spin(360 / 48) // change color hue
right(360 / 48)
}
invisible()