Colour Changing Vibrant Circle in Python

import turtle
tur=turtle.Turtle()
scr=turtle.Screen()
scr.bgcolor('black')
tur.pencolor('white')
x=0
y=0
tur.speed(0)
tur.penup()
tur.pendown()
colors = ['red', 'purple', 'blue', 'green', 'orange', 'yellow']
while True:
tur.pencolor(colors[y%6])
tur.forward(x)
tur.right(y)
x +=3
y +=1
if y==210:
break

tur.hideturtle()
turtle.done()