#include <Adafruit_NeoPixel.h>

#define PIN_LED    6
#define NUMPIXELS  30
#define PIN_TOUCH  2

Adafruit_NeoPixel pixels(NUMPIXELS, PIN_LED, NEO_GRB + NEO_KHZ800);

int mode = 0; // 0 = éteint, 1 = blanc, 2 = bleu, 3 = rose...

void setup() {
  pixels.begin();
  pinMode(PIN_TOUCH, INPUT);
}

void loop() {
  if (digitalRead(PIN_TOUCH) == HIGH) {
    mode = (mode + 1) % 4;
    delay(300); // anti-rebond
  }

  switch(mode) {
    case 0: setColor(0, 0, 0); break;          // éteint
    case 1: setColor(255, 220, 180); break;    // blanc chaud
    case 2: setColor(0, 100, 255); break;      // bleu
    case 3: setColor(255, 50, 100); break;     // rose
  }
}

void setColor(byte r, byte g, byte b) {
  for(int i=0; i<NUMPIXELS; i++) {
    pixels.setPixelColor(i, pixels.Color(r, g, b));
  }
  pixels.show();
}