Color dust particld

How mak random color for dust particles ?

For how to spawn a particle, search the forums.
For how to select a completely random color:

PHP:

$r = mt_rand(0, 255);
$g = mt_rand(0, 255);
$b = mt_rand(0, 255);

What can you tell what color the figure represents?

$r $g $b are the RGB representation of colors. For more info, Google it.