import random

import pygame
pygame.init()

szerokosc = 800
wysokosc = 600
screen = pygame.display.set_mode((szerokosc, wysokosc))
pygame.display.set_caption("App 1")

clock = pygame.time.Clock()

screen.fill((20,20,20))
working = True

while working:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            working = False
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_6:
             screen.fill((20,20,20))
    mouse = pygame.mouse.get_pressed()
    if mouse[0]:
       pos = pygame.mouse.get_pos()
       kolor = (random.randint(0,255), random.randint(0,255), random.randint(0,255))
       pygame.draw.circle(screen, kolor, pos, 8, 2)

    pygame.display.flip()
    clock.tick(100000)

pygame.quit