function str_to_colorcode(
          $str,
          $range = array(
             'h' => array('base' => 0,'lim' => 360),
             's' => array('base' => 0,'lim' => 100),
             'v' => array('base' => 0,'lim' => 100)),
          $salt = 0)
{
 if(!isset($str))
  return flase;

 static $tarr = array(
                  0 => array('r' => 'v','g' => 'k','b' => 'm'),
                  1 => array('r' => 'n','g' => 'v','b' => 'm'),
                  2 => array('r' => 'm','g' => 'v','b' => 'k'),
                  3 => array('r' => 'm','g' => 'n','b' => 'v'),
                  4 => array('r' => 'k','g' => 'm','b' => 'v'),
                  5 => array('r' => 'v','g' => 'm','b' => 'n'));

 $str = sha1($str . $salt);
 $s   = ($range['s']['base'] + abs(hexdec(substr($str,10,10)) % $range['s']['lim'])) *  .01;
 $v   = ($range['v']['base'] + abs(hexdec(substr($str,20,10)) % $range['v']['lim'])) * 2.55;

 if($s == 0)
  $c = array('r' => $v,'g' => $v,'b' => $v);
 else
 {
  $h = $range['h']['base'] + abs(hexdec(substr($str, 0,10)) % $range['h']['lim']);
  $i = floor($h / 60);
  $f = $h / 60 - $i;
  $arr = array(
         'v' => $v,
         'm' => $v * (1 - $s),
         'n' => $v * (1 - $s * $f),
         'k' => $v * (1 - $s * (1 - $f))
         );
  $c = array('r' => $arr[$tarr[$i]['r']],'g' => $arr[$tarr[$i]['g']],'b' => $arr[$tarr[$i]['b']]);
 }

 return sprintf('#%02x%02x%02x',floor($c['r']),floor($c['g']),floor($c['b']));
}

$str   : 対象になる文字列
$range : HSVの各要素の基準と範囲を入れた配列
         $range['h']['base'] : 色相(H)の基準を0 〜 359で
         $range['h']['lim']  : 色相(H)の範囲を0以上＆基準との合計が360以下で
         $range['s']['base'] : 彩度(S)の基準を0 〜 100で
         $range['s']['lim']  : 彩度(S)の範囲を0以上＆基準との合計が101以下で
         $range['v']['base'] : 明度(V)の基準を0 〜 100で
         $range['v']['lim']  : 明度(V)の範囲を0以上＆基準との合計が101以下で
$salt  : 味付け用の引数