Warm or cool light: a knob blends an RGB LED, on an Arduino Uno

// Cool or warm: a knob on A0 blends an RGB LED from warm to cool.
//
//   RGB red -> 220 ohm -> pin 11   green -> 220 ohm -> pin 10
//   RGB blue -> 220 ohm -> pin 9   the long common leg -> GND
//   potentiometer: ends to 5V and GND, middle leg -> A0
//
// A warm white is mostly red with some green and little blue; a cool one is
// mostly blue. map() slides each channel from its warm value to its cool one
// as the knob turns, so halfway round you get halfway between.

const int RED = 11;
const int GREEN = 10;
const int BLUE = 9;

const int WARM[3] = {246, 52, 8};
const int COOL[3] = {100, 150, 255};

void setup() {
  pinMode(RED, OUTPUT);
  pinMode(GREEN, OUTPUT);
  pinMode(BLUE, OUTPUT);
  Serial.begin(9600);
  Serial.println("Mokxi Uno: turn the knob from warm to cool");
}

void loop() {
  int knob = analogRead(A0);
  int r = map(knob, 0, 1023, WARM[0], COOL[0]);
  int g = map(knob, 0, 1023, WARM[1], COOL[1]);
  int b = map(knob, 0, 1023, WARM[2], COOL[2]);
  analogWrite(RED, r);
  analogWrite(GREEN, g);
  analogWrite(BLUE, b);
  Serial.print("R ");
  Serial.print(r);
  Serial.print("  G ");
  Serial.print(g);
  Serial.print("  B ");
  Serial.println(b);
  delay(200);
}