from __future__ import division

size(300, 260)

background(255)  # white

x = floor(random(width))
y = floor(random(height))

for _ in range(30000):
    v = floor(random(3))
    if v == 0:
        x = x / 2
        y = y / 2
        colour = color(0, 255, 0)  # green
    elif v == 1:
        x = width / 2 + (width / 2 - x) / 2
        y = height - (height - y) / 2
        colour = color(255, 0, 0)  # red
    elif v == 2:
        x = width - (width - x) / 2
        y = y / 2
        colour = color(0, 0, 255)  # blue

    set(x, height - y, colour)