public function setColor( $key, $r, $g, $b, $alpha = 0, $range = 0 )
	{
		#	Set color
	
		if( !in_array( $key, array( 'background', 'background_text', 'front_text' ) ) )
			throw new CaptchaException( __METHOD__ . '($key, ) must be one of( background, background_text, front_text ).' );
		
		if( !is_numeric( $r ) || !is_numeric( $g ) || !is_numeric( $b ) || !is_numeric( $alpha ) || !is_numeric( $range ) )
			throw new CaptchaException( __METHOD__ . '( , $args ) second argument and the followers must be numeric values.' );

		# set values
		$property = ( $key == 'background' ) ? '_image_info' : '_' . $key;


		$this->{$property}['color']				= array( $r, $g, $b, $alpha );
		$this->{$property}['color']['range'] 	= $range;
		
		return $this;
		# Method End
	}