Color

    // color swirl! connect an RGB LED to the PWM pins as indicated
    // in the #defines
    // public domain, enjoy!

    #define REDPIN 16
    #define GREENPIN 5
    #define BLUEPIN 4

    #define FADESPEED 5     // make this higher to slow down

    void setup() {
      pinMode(REDPIN, OUTPUT);
      pinMode(GREENPIN, OUTPUT);
      pinMode(BLUEPIN, OUTPUT);
    }


    void loop() {
      int r, g, b;

      // fade from blue to violet
      for (r = 0; r < 256; r++) {
        analogWrite(REDPIN, r);
        delay(FADESPEED);
      }
      // fade from violet to red
      for (b = 255; b > 0; b--) {
        analogWrite(BLUEPIN, b);
        delay(FADESPEED);
      }
      // fade from red to yellow
      for (g = 0; g < 256; g++) {
        analogWrite(GREENPIN, g);
        delay(FADESPEED);
      }
      // fade from yellow to green
      for (r = 255; r > 0; r--) {
        analogWrite(REDPIN, r);
        delay(FADESPEED);
      }
      // fade from green to teal
      for (b = 0; b < 256; b++) {
        analogWrite(BLUEPIN, b);
        delay(FADESPEED);
      }
      // fade from teal to blue
      for (g = 255; g > 0; g--) {
        analogWrite(GREENPIN, g);
        delay(FADESPEED);
      }
    }