Simple LED code needed for ambient lighting

I am looking for code for an Arduino Nano which will allow me to define a palette and have the palette run through a slow shifting pattern where the colors change slowly back and forth. An example of the pattern is (as you can tell my programming knowledge is very very limited):

#include <FastLED.h>

#define NUM_LEDS 100
#define LED_PIN 5

CRGB leds[NUM_LEDS];

void setup() {
FastLED.addLeds<WS2812B, LED_PIN, GRB>(leds, NUM_LEDS);
FastLED.setBrightness(100);
Serial.begin(15600);
}

void loop() {
uint8_t octaves = 2;
uint16_t x=1;
int scale = 1;
uint8_t hue_octaves = 1;
uint16_t hue_x=1;
int hue_scale = 20;
uint16_t ntime = millis() / 5;
uint8_t hue_shift = 20;

fill_noise16 (leds, NUM_LEDS, octaves, x, scale, hue_octaves, hue_x, hue_scale, ntime, hue_shift);

FastLED.show();
}

Would like to be able to use a similar pattern, with variable speed which I can program with a potentiometer, and have it cycle through the defined palette which can be obtained from paletteknife. Being able to use palette part is important

It is for ambient lighting for my car since I cannot (anywhere close to) afford a Mercedes Benz S-class.

Offering $150.00

Hello, do yourself a favour and please read How to get the best out of this forum and modify your post accordingly (including code tags and necessary documentation of your ask).

➜ code tags
➜ explain what "paletteknife" is and how this has to be integrated