// https://wokwi.com/projects/363128769711260673
// https://forum.arduino.cc/t/custom-nano-leaf-project/1119959

# include <FastLED.h>

const uint8_t startGroup1 = 0;
const uint8_t lengthGroup1 = 10;
const uint8_t startGroup2 = lengthGroup1;
const uint8_t lengthGroup2 = 7;
const uint8_t startGroup3 = startGroup2 + lengthGroup2;
const uint8_t lengthGroup3 = 13;
const uint8_t ledPin = 6;

const uint8_t ledCount = lengthGroup1 + lengthGroup2 + lengthGroup3;

CRGB leds[ledCount];

CRGBSet group1(leds, startGroup1, startGroup1 + lengthGroup1 - 1);
CRGBSet group2(leds, startGroup2, startGroup2 + lengthGroup2 - 1);
CRGBSet group3(leds, startGroup3, startGroup3 + lengthGroup3 - 1);

void setup() {

  FastLED.addLeds<WS2812B, ledPin, GRB>(leds, ledCount);

  group1 = CRGB::Red;
  group2 = CRGB::Green;
  group3 = CRGB::Blue;

  FastLED.show();
  delay(1777);

  group1[1] = CRGB::White;
  group2[3] = CRGB::Yellow;
  group3[5] = CRGB::Magenta;

  group1[19] = CRGB::Cyan;  // doesn't prevent
  group2[-2] = CRGB::Cyan;  // also doesn't prevent

  FastLED.show();
}

void loop() {}