from machine import Pin
from neopixel import NeoPixel
from time import sleep

pixel_pin  = 22
num_pixels = 16

pixels = NeoPixel(Pin(pixel_pin ), num_pixels)

pixels.fill((255, 0, 0)); pixels.write(); sleep(1)
print(pixels)
print(pixels[1])
print(pixels[1][0])
# pixels[1][2]=255  #TypeError: 'tuple' object doesn't support item assignment
# pixels[1]=(pixels[1][0]-100,pixels[1][1]+100,pixels[1][2]
pixels[1]=(pixels[1][0]-100,pixels[1][1]+100,pixels[1][2])
pixels.write(); sleep(1)

def change_pixels(i,dr,dg,db):
    pixels[i]=(pixels[1][0]+dr,pixels[1][1]+dg,pixels[1][2]+db)
    pixels.write();

change_pixels(4,-100,100,200)