from machine import Pin
import time
Red = Pin(25, Pin.OUT)
Green = Pin(26, Pin.OUT)
Blue = Pin(27, Pin.OUT)
sw = Pin(0, Pin.IN)

def set_led():
    Red.value(1)
    Green.value(0)
    Blue.value(0)
    time.sleep_ms(300)
    Red.value(0)
    Green.value(1)
    Blue.value(0)
    time.sleep_ms(300)
    Red.value(0)
    Green.value(0)
    Blue.value(1)
    time.sleep_ms(300)

sw.irq(trigger=Pin.IRQ_FALLING,handler= set_led)