import RPi.GPIO as GPIO
from time import sleep
GPIO.setmode(GPIO.BCM)
RED=16; BLUE=20; GREEN=21;
GPIO.setup(RED,GPIO.OUT); GPIO.output(RED,0);
GPIO.setup(GREEN,GPIO.OUT); GPIO.output(GREEN,0);
GPIO.setup(BLUE,GPIO.OUT); GPIO.output(BLUE,0)
#---ctrl-c to terminate the loop----
for jc in range(200):
    j=jc%8;  #j=7 #turn off LED
    r=j%2; g=j//2%2; b=j//4%2;
    print('jc=',jc,j,(r,g,b))
    GPIO.output(RED,r);
    GPIO.output(GREEN,g);
    GPIO.output(BLUE,b);
    if(j==5): sleep(4)
    elif(j==6): sleep(2)
    elif(j==3): sleep(0.2)
    elif(j==7): sleep(0.2)
    else: sleep(0.2)