Add Color to PHP Echo in CLI

I adapted this PHP script from If Not True Then False for CentOS escape codes, which use a semi-colon and not a comma between bold and color codes for foreground color escaping.

[Update Sep 3, 2012] This code is now available on github as part of the Box Bart project.

The newer code has __callStatic magic letting you type EscapeColors::red('Some warning message'); in place of the wordier (and less obvious) EscapeColors::fg_color('red', 'Some warning message');

/**
 * Color escapes for bash output
 */
class Escape_Colors
{
 private static $foreground = array(
  'black' => '0;30',
  'dark_gray' => '1;30',
  'red' => '0;31',
  'bold_red' => '1;31',
  'green' => '0;32',
  'bold_green' => '1;32',
  'brown' => '0;33',
  'yellow' => '1;33',
  'blue' => '0;34',
  'bold_blue' => '1;34',
  'purple' => '0;35',
  'bold_purple' => '1;35',
  'cyan' => '0;36',
  'bold_cyan' => '1;36',
  'white' => '1;37',
  'bold_gray' => '0;37',
 );

 private static $background = array(
  'black' => '40',
  'red' => '41',
  'magenta' => '45',
  'yellow' => '43',
  'green' => '42',
  'blue' => '44',
  'cyan' => '46',
  'light_gray' => '47',
 );

 /**
  * Make string appear in color
  */
 public static function fg_color($color, $string)
 {
  if (!isset(self::$foreground[$color]))
  {
   throw new Exception('Foreground color is not defined');
  }

  return "\033[" . self::$foreground[$color] . "m" . $string . "\033[0m";
 }

 /**
  * Make string appear with background color
  */
 public static function bg_color($color, $string)
 {
  if (!isset(self::$background[$color]))
  {
   throw new Exception('Background color is not defined');
  }

  return "\033[" . self::$background[$color] . 'm' . $string . "\033[0m";
 }

 /**
  * See what they all look like
  */
 public static function all_fg()
 {
  foreach (self::$foreground as $color => $code)
  {
   echo "$color - " . self::fg_color($color, 'Hello, world!') . PHP_EOL;
  }
 }

 /**
  * See what they all look like
  */
 public static function all_bg()
 {
  foreach (self::$background as $color => $code)
  {
   echo "$color - " . self::bg_color($color, 'Hello, world!') . PHP_EOL;
  }
 }
}