modify inoise8_pal_demo_fastLed.ino to use custom palettes arbitrarily.

inoise8_pal_demo_fastLed_mod1.ino

//  https://pastebin.com/r70Qk6Bn


/* Title: inoise8_pal_demo.ino
 * 
 * By: Andrew Tuline
 * 
 *  Added custom color palettes arbitrarily selectable.
 */
 

#include "FastLED.h"

#if FASTLED_VERSION < 3001000
#error "Requires FastLED 3.1 or later; check github for latest code."
#endif

#define LED_PIN     2
//#define CLK_PIN     11
#define BRIGHTNESS  255
#define LED_TYPE    WS2812B      // Only use the LED_PIN for WS2812's
#define COLOR_ORDER GRB

#define NUM_LEDS 43

struct CRGB leds[NUM_LEDS];

static uint16_t dist;         // A random number for our noise generator.
uint16_t scale = 30;          // Wouldn't recommend changing this on the fly, or the animation will be really blocky.
uint8_t maxChanges = 48;      // Value for blending between palettes.

//  Summer fades to Autumn Color Palette:
//  SFTA
// http://www.color-hex.com/color-palette/10894
CRGB SFTA0 = CRGB(88,140,115);
CRGB SFTA1 = CRGB(242,174,148);
CRGB SFTA2 = CRGB(242,174,114);
CRGB SFTA3 = CRGB(217,100,89);
CRGB SFTA4 = CRGB(140,70,70);
//extern CRGBPalette16 summerFadesToAutumnPalette;
//extern const TProgmemPalette16 summerFadesToAutumnPalette_p PROGMEM;

const TProgmemPalette16 summerFadesToAutumnPalette_p PROGMEM =
{
    SFTA0,
    SFTA1, 
    SFTA2,
    SFTA3,
    SFTA4,
    
    SFTA0,
    SFTA1,
    SFTA2,
    SFTA3,
    SFTA4,
    
    SFTA0,
    SFTA1,
    SFTA2,
    SFTA3,
    SFTA4,
    
    SFTA0
};


//  Autumn Color Palette:
// http://www.color-hex.com/color-palette/1278

CRGB AC0 = CRGB(255,210,0);
CRGB AC1 = CRGB(155,87,8);
CRGB AC2 = CRGB(244,123,32);
CRGB AC3 = CRGB(247,151,98);
CRGB AC4 = CRGB(240,81,51);
//extern CRGBPalette16 autumnColorPalette;
//extern const TProgmemPalette16 autumnColorPalette_p PROGMEM;

const TProgmemPalette16 autumnColorPalette_p PROGMEM =
{
    AC0,
    AC1, 
    AC2,
    AC3,
    AC4,
    
    AC0,
    AC1,
    AC2,
    AC3,
    AC4,
    
    AC0,
    AC1,
    AC2,
    AC3,
    AC4,
    
    AC0
};


// Colors of Autumn Color Palette
// http://www.color-hex.com/color-palette/10153
CRGB COA0 = CRGB(251,54,54);
CRGB COA1 = CRGB(234,199,56);
CRGB COA2 = CRGB(240,249,97);
CRGB COA3 = CRGB(210,236,0);
CRGB COA4 = CRGB(122,195,19);
//extern CRGBPalette16 colorsOfAutumnPalette;
//extern const TProgmemPalette16 colorsOfAutumnPalette PROGMEM;

const TProgmemPalette16 colorsOfAutumnPalette_p PROGMEM =
{
    COA0,
    COA1, 
    COA2,
    COA3,
    COA4,
    
    COA0,
    COA1, 
    COA2,
    COA3,
    COA4,
    
    COA0,
    COA1, 
    COA2,
    COA3,
    COA4,
    
    COA0
};


CRGBPalette16 currentPalette(CRGB::Black);
CRGBPalette16 targetPalette(summerFadesToAutumnPalette_p);

const TProgmemRGBPalette16* ActivePaletteList[] = {
  summerFadesToAutumnPalette_p,
  autumnColorPalette_p,
  colorsOfAutumnPalette_p
};



void setup() 
{
  Serial.begin(57600);
  delay(3000);
  
  LEDS.addLeds<LED_TYPE,LED_PIN,COLOR_ORDER>(leds,NUM_LEDS);

  LEDS.setBrightness(BRIGHTNESS);
  dist = random16(12345);          // A semi-random number for our noise generator

  chooseNextColorPalette(targetPalette);
  
}


void loop() {
  EVERY_N_MILLISECONDS(10) {
    nblendPaletteTowardPalette(currentPalette, targetPalette, maxChanges);  // Blend towards the target palette
    fillnoise8();                                                           // Update the LED array with noise at the new location
  }

  EVERY_N_SECONDS(5) {             // Change the target palette to a random one every 5 seconds.
    chooseNextColorPalette( targetPalette ); 
  }

  LEDS.show();                    // Display the LED's at every loop cycle.
} 


void fillnoise8() {
  for(int i = 0; i < NUM_LEDS; i++) {                                      // Just ONE loop to fill up the LED array as all of the pixels change.
    uint8_t index = inoise8(i*scale, dist+i*scale) % 255;                  // Get a value from the noise function. I'm using both x and y axis.
    leds[i] = ColorFromPalette(currentPalette, index, 255, LINEARBLEND);   // With that value, look up the 8 bit colour palette value and assign it to the current LED.
  }
  dist += beatsin8(10,1, 4);                                               // Moving along the distance (that random number we started out with). Vary it a bit with a sine wave.
                                                                           // In some sketches, I've used millis() instead of an incremented counter. Works a treat.
} 


// Advance to the next color palette in the list (above).
void chooseNextColorPalette( CRGBPalette16& pal)
{
  const uint8_t numberOfPalettes = sizeof(ActivePaletteList) / sizeof(ActivePaletteList[0]);
  static uint8_t whichPalette = -1; 
  whichPalette = addmod8( whichPalette, 1, numberOfPalettes);

  pal = *(ActivePaletteList[whichPalette]);
}