Python精灵模块的collidecolor指令

import time
from sprites import Sprite,Mouse,mouse_pos

arrow = Sprite("a.png")
c1= (255,0,0)                  # 箭头上的红色
square = Sprite("square.png")
square2 = Sprite("square.png")
square2.gotorandom()

c2 = (0,0,250)                 # 方块上的蓝色
c3 = (250,0,0)                 # 方块上的红色
screen= arrow.getscreen()      # 获取屏幕对象

leftkey = Mouse()              # 实例化鼠标左键
while True:
    mx,my = mouse_pos()
    arrow.goto(mx,my)
    if leftkey.downup():    # 如果鼠标左键接下并松开 
        arrow.left(90)      # 左转90度
    r = arrow.collidecolor(c2) # 箭头是否碰到两个方块中的c2颜色?
    print(r)
    screen.update()