PHP Rainbow BB Code Generator

rainbow.php

<?php
class Rainbow
{
	private $colors;
	
	public function __construct() {
		$this->colors = array(
			'ff00ff', 'ff00cc', 'ff0099', 'ff0066', 'ff0033', 'ff0000', 'ff3300', 'ff6600', 'ff9900', 'ffcc00', 'ffff00', 'ccff00', '99ff00', '66ff00', '33ff00', '00ff00', '00ff33', '00ff66', '00ff99', '00ffcc', '00ffff', '00ccff', '0099ff', '0066ff', '0033ff', '0000ff', '3300ff', '6600ff', '9900ff', 'cc00ff'
		);
	}
	
	public function bbCode($text, $color) {
		if ($text != " ") {
			return "[color=\"#" . $color . "\"]" . $text . "[/color]";
		}
		else {
			return " ";
		}
	}
	
	public function pickColor($text) {
		return count($this->colors) / strlen($text);
	}
	
	public function generateBB($text) {
		$code = "";
		$texts = str_split($text, count($this->colors));
		foreach ($texts as $t) {
			for ($i = 0; $i < strlen($t); $i++) {
				$code .= $this->bbCode($t[$i], $this->colors[(int) $this->pickColor($t) * $i]);
			}
		}
		return $code;
	}
}

$rainbow = new Rainbow();

if (isset($_GET["str"])) {
	echo $rainbow->generateBB($_GET["str"]);
}
else {
	echo "Usage: ?str=[text2TurnIntoRainbowBbCode]";
}
?>