2.py

import turtle

pen = turtle.Pen()
a = 1
pen.speed(0)
for i in range(300):
    pen.color("red")
    pen.forward(a)
    pen.right(91)
    a += 0.5
    pen.color("yellow")
    pen.forward(a)
    pen.right(91)
    a += 0.5
    pen.color("green")
    pen.forward(d)
    pen.right(91)
    d += 0.5
    pen.color("blue")
    pen.forward(d)
    pen.right(91)
    d += 0.5
pen.hideturtle()
turtle.done()