import turtle
t = turtle.Turtle()
s = turtle.screen()
s.bgcolor('black')
t.speed(0)
col=("yellow","red","pink")
for i in range(150):
    t.pencolor(col[i%3])
    t.lt(90)
    t.circle(190-i/3,90)
    t.lt(60)
s.exitonclick()