Remote-controlled colors: IR on pin 2, RGB on 11, 10 and 9, on an Arduino Uno

// A remote-controlled light: number buttons pick the RGB LED's color.
//
//   IR receiver OUT -> pin 2   VCC -> 5V   GND -> GND
//   RGB red -> 220 ohm -> pin 11   green -> 220 ohm -> pin 10
//   RGB blue -> 220 ohm -> pin 9   the long common leg -> GND
//
// Each button on the remote sends its own command number. The receiver
// decodes it, keyOf() turns it into the label on the button, and the label
// picks a color: 1 to 7 are red, orange, yellow, green, blue, indigo and
// violet, and 0 is off.
//
// Click a number on the remote on the canvas.

// The simulated remote speaks NEC, so only that decoder is compiled in.
#define DECODE_NEC
#include <IRremote.hpp>

// The remote's buttons by the command each one sends.
const char *keyOf(uint8_t command) {
  switch (command) {
    case 0x16: return "0";
    case 0x0C: return "1";
    case 0x18: return "2";
    case 0x5E: return "3";
    case 0x08: return "4";
    case 0x1C: return "5";
    case 0x5A: return "6";
    case 0x42: return "7";
    case 0x52: return "8";
    case 0x4A: return "9";
    case 0x45: return "CH-";
    case 0x46: return "CH";
    case 0x47: return "CH+";
    case 0x44: return "PREV";
    case 0x40: return "NEXT";
    case 0x43: return "PLAY/PAUSE";
    case 0x07: return "VOL-";
    case 0x15: return "VOL+";
    case 0x09: return "EQ";
    case 0x19: return "100+";
    case 0x0D: return "200+";
    default: return "";
  }
}

const int RECEIVER = 2;
const int RED = 11;
const int GREEN = 10;
const int BLUE = 9;

const int RAINBOW[8][3] = {
  {0, 0, 0},       // 0: off
  {255, 0, 0},     // 1: red
  {255, 80, 0},    // 2: orange
  {255, 200, 0},   // 3: yellow
  {0, 255, 0},     // 4: green
  {0, 0, 255},     // 5: blue
  {75, 0, 130},    // 6: indigo
  {160, 0, 255},   // 7: violet
};

void setup() {
  pinMode(RED, OUTPUT);
  pinMode(GREEN, OUTPUT);
  pinMode(BLUE, OUTPUT);
  Serial.begin(9600);
  IrReceiver.begin(RECEIVER, ENABLE_LED_FEEDBACK);
  Serial.println("Mokxi Uno: press 0 to 7 on the remote");
}

void loop() {
  if (!IrReceiver.decode()) return;
  bool repeat = IrReceiver.decodedIRData.flags & IRDATA_FLAGS_IS_REPEAT;
  const char *key = keyOf(IrReceiver.decodedIRData.command);
  IrReceiver.resume();
  if (repeat || key[0] < '0' || key[0] > '7' || key[1] != '\0') return;
  int n = key[0] - '0';
  analogWrite(RED, RAINBOW[n][0]);
  analogWrite(GREEN, RAINBOW[n][1]);
  analogWrite(BLUE, RAINBOW[n][2]);
  Serial.print("button ");
  Serial.println(key);
}