WS2811 LEd strip RPI3B+ flashing cloud

Question

I want to build similar project like this https://youtu.be/EoGVQl3SjGY but with use of RPI 3B+

I only need to code 20LEDs (one strip) to flash randomly in various intensity and colours from (80,0,150) to (200,0,255),, no sound reactivity (only lights).

I have all hardware setup well, using adafruit library ws281x bud don't know how to code an infinite loop of flashing..

my code for now is:

from rpi_ws281x import *
import random

# LED strip configuration:
LED_COUNT      = 20      # Number of LED pixels.
LED_PIN        = 10      # GPIO pin connected to the pixels (18 uses PWM!).
#LED_PIN        = 10      # GPIO pin connected to the pixels (10 uses SPI /dev/spidev0.0).
LED_FREQ_HZ    = 800000  # LED signal frequency in hertz (usually 800khz)
LED_DMA        = 10      # DMA channel to use for generating signal (try 10)
LED_BRIGHTNESS = 255   # Set to 0 for darkest and 255 for brightest
LED_INVERT     = False   # True to invert the signal (when using NPN transistor level shift)
LED_CHANNEL    = 0       # set to '1' for GPIOs 13, 19, 41, 45 or 53

strip = Adafruit_NeoPixel(LED_COUNT, LED_PIN, LED_FREQ_HZ,LED_DMA,LED_INVERT,LED_BRIGHTNESS,LED_CHANNEL)
strip.begin()

for x in range(0,LED_COUNT):
    while True:
        R = random.randint(80,200)
        B = random.randint(150,255)
        strip.setPixelColor(x,Color(R,0,B))

strip.show()

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I know I need to somehow set the While true loop to flash/animate LEDs randomly (like with noise effect). For now all the leds are still.

Thanks in advance for help..

Ereen