Random number for RGB Led

Using Arduino Programming Questions
6

The original arrangement of lighting up just one color per led is weird, particularly in light of the multiple leds.

Here is what I would do:

#define LED_RAND(led) do {if (random(0, 2)) lightBlue(led); if (random(0, 2)) lightRed(led); if (random(0, 2)) lightGreen(led);} while (0);

//in your application code:

  LED_RAND(led1); //randomly lite up a led
  LED_RAND(led2); //randomly lite up a led
...
  LED_RAND(led9); //randomly lite up a led

It will produce random patterns on each led, up to 8 combinations (including dark/off).