Code Sketch

clear() 
setSpeed(fast) 
setBackground(white)
def square(n: Int) 
{ 
    repeat(4) { 
        forward(n) 
        right(90)
} 
} //> def square(n: Int): Unit
setPenColor(black)
var clr = cm.red.fadeOut(0.9) //> var clr: net.kogics.kojo.doodle.HSLA = HSLA(Angle(0.0),Normalized(1.0),Normalized(0.5),Normalized(0.09999999999999998))
repeat(19) { 
    setFillColor(clr) 
    square(90) 
    right(30) 
    clr = clr.spin(30)
}