from machine import Pin # import the pins
import time # import the time delay

SWITCH = Pin(13, Pin.IN)   # set pin 13 as input pin object for the switch
RED = Pin(21, Pin.OUT)     # set pin 21 as an output pin object for the RED LED
GREEN = Pin(19, Pin.OUT)   # set pin 19 as an output pin object for the GREEN LED
BLUE = Pin(18, Pin.OUT)    # set pin 18 as an output pin object for the BLUE LED
YELLOW = Pin(5, Pin.OUT)   # set pin 5 as an output pin object for the YELLOW LED

while True:  # run an infinite loop
    if SWITCH.value() == 1:  # if the switch is turned on
        RED.value(1)   # turn on the red LED
        GREEN.value(1)   # turn on the green LED
        BLUE.value(1)   # turn on the blue LED
        YELLOW.value(0)   # turn off the yellow LED
        time.sleep(0.5)   # delay for half a second
        BLUE.value(0)   # turn off the blue LED
        YELLOW.value(1)   # turn on the yellow LED
        time.sleep(0.5)   # delay for half a second

    if SWITCH.value() == 0:  # if the switch is turned off
        BLUE.value(1)   # turn on the blue LED
        YELLOW.value(1)   # turn on the yellow LED
        RED.value(1)   # turn on the red LED
        GREEN.value(0)   # turn off the green LED
        time.sleep(0.5)   # delay for half a second
        RED.value(0)   # turn off the red LED
        GREEN.value(1)   # turn on the green LED
        time.sleep(0.5)   # delay for half a second