编写程序，程序开始运行时在界面中显示一个白色的圆有黑色边框，当在圆中按下鼠标键时颜色变为蓝色，释放鼠标时颜色为红色。

好的，这是一个基于 Python3 的 Pygame 库的程序，可以在 Pygame 环境下运行。以下是代码：

import pygame

pygame.init()

screen = pygame.display.set_mode((400, 400))
pygame.display.set_caption("Colorful Circle")

WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
BLUE = (0, 0, 255)
RED = (255, 0, 0)

circle_color = WHITE
circle_radius = 50
circle_position = (200, 200)

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()
        if event.type == pygame.MOUSEBUTTONDOWN:
            if pygame.mouse.get_pos()[0] >= circle_position[0] - circle_radius and \
                    pygame.mouse.get_pos()[0] <= circle_position[0] + circle_radius and \
                    pygame.mouse.get_pos()[1] >= circle_position[1] - circle_radius and \
                    pygame.mouse.get_pos()[1] <= circle_position[1] + circle_radius:
                circle_color = BLUE
        elif event.type == pygame.MOUSEBUTTONUP:
            if pygame.mouse.get_pos()[0] >= circle_position[0] - circle_radius and \
                    pygame.mouse.get_pos()[0] <= circle_position[0] + circle_radius and \
                    pygame.mouse.get_pos()[1] >= circle_position[1] - circle_radius and \
                    pygame.mouse.get_pos()[1] <= circle_position[1] + circle_radius:
                circle_color = RED

    screen.fill(WHITE)
    pygame.draw.circle(screen, BLACK, circle_position, circle_radius, 2)
    pygame.draw.circle(screen, circle_color, circle_position, circle_radius - 2)
    pygame.display.update()

程序运行后会在 Pygame 窗口中显示一个白色的圆，当你按下鼠标键在圆内时，圆的颜色会变为蓝色，松开鼠标键时颜色会变为红色。