from machine import Pin
from utime import sleep

red_pin = Pin(0, Pin.OUT)
green_pin = Pin(2, Pin.OUT)
blue_pin = Pin(15, Pin.OUT)

def sub_rgb_led():
  red_pin.value(0) 
  green_pin.value(1) 
  blue_pin.value(1) 
  sleep(0.5) 
   
  red_pin.value(1) 
  green_pin.value(0) 
  blue_pin.value(1) 
  sleep(0.5) 
   
  red_pin.value(1) 
  green_pin.value(1) 
  blue_pin.value(0) 
  sleep(0.5) 


while True:
    sub_rgb_led()

# the led show the change of colour from red,green to blue and be delay for 0.5 second.