#include <FastLED.h>

const int numLeds = 30;
const int ledStripPin = 6;

CRGB leds[numLeds];

void setup() {
  FastLED.addLeds<NEOPIXEL, ledStripPin>(leds, numLeds);
  FastLED.setMaxPowerInVoltsAndMilliamps(5, 400);
  FastLED.setBrightness(8);
  pinMode(2, INPUT_PULLUP);
}

void loop() {
  if (digitalRead(2) == LOW) {
    cycleColours();
  }
}
void cycleColours() {
  for (int light=0; light<30; light++) {
      leds[light] = CRGB::Red;
    }
    FastLED.show();
    delay(1000);
    for (int light=0; light<30; light++) {
      leds[light] = CRGB::Blue;
    }
    FastLED.show();
    delay(1000);
    for (int light=0; light<30; light++) {
      leds[light] = CRGB::Yellow;
    }
    FastLED.show();
    delay(1000);
    for (int light=0; light<30; light++) {
      leds[light] = CRGB::Green;
    }
    FastLED.show();
    delay(1000);
    for (int light=0; light<30; light++) {
      leds[light] = CRGB::Purple;
    }
    FastLED.show();
    delay(1000);
}