Tricolour

A NeoPixel stick (8 LEDs): DIN on GPIO18, powered from 5 V. Paint a flag:

• pixels 0–2 blue (0, 0, 255)
• pixels 3–4 white (255, 255, 255)
• pixels 5–7 red (255, 0, 0)

Tip: slices work — pixels[0:3] = [(0, 0, 255)] * 3.