Neopixel help.

Using Arduino LEDs and Multiplexing
1

I have made the neopixels adjust their brightness to music, using a sparkfun sound detector.

However I cannot work out how to change the colour as well. E.G if the sound detector detects a loud beat then the neopixels go red.

My thinking was to use a if statement to check if the sound value is greater than a certain amount, then set the colours. Red = 255, Green = 0 and Blue = 0.

I think due to the for loop I am using, this mucks it up, I've tried everything I can think of but each time they all just go off.

Here is my code :

#define PIN_GATE_IN 2
#define IRQ_GATE_IN  0
#define PIN_LED_OUT 13
#define PIN_ANALOG_IN A0

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
  #include <avr/power.h>
#endif

#define PIN 6

Adafruit_NeoPixel strip = Adafruit_NeoPixel(15, PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(PIN_GATE_IN, INPUT);

  #if defined (__AVR_ATtiny85__)
    if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
  #endif

  strip.begin();
  strip.show();

}

void loop() {

  int green = 0;
  int red = 0;
  int blue = 0;
  int x;
  int value;
  int n = 1;
  int intensity;
  
  value = analogRead(PIN_ANALOG_IN);

  intensity = map(value, 0, 500, 0, 64);

  for (x = 1; x < 15; x++) {

    red = 255;
    green = 255;
    blue = 0;

    strip.setPixelColor(n, red, green, blue);
    strip.show();
    n = n+1;
    strip.setBrightness(intensity); }

}

This is without attempting the if statements

2

Why not mapping the analog reading directly to the red value:

void loop() {

  value = analogRead(PIN_ANALOG_IN);

  red = value / 4;

  for (x = 0; x < 15; x++) {

    strip.setPixelColor(x, red, 0, 0);   
  
  }

  strip.show();

}