Set up ido mode in emacs 21

I am using ido mode. and GNUM emacs 21.1.1 on AIX. I add the ido.el in the .emacs.d. and add the following in the .emacs file.

(load-file "~/.emacs.d/site-lisp/ido/ido.el")
(require 'ido)
(ido-mode t)
(setq ido-enable-flex-matching t) ;; enable fuzzy matching

When start emacs, it complains. and there is no ido-mode. How to fix this?

error: "Unknown req `min-colors' with options `(88)'"

To ensure normal operation, you should investigate the cause
of the error in your initialization file and remove it.  Start
Emacs with the `--debug-init' option to view a complete error
backtrace

contents of the backtrace

Debugger entered--Lisp error: (error "Unknown req `min-colors' with options `(88)'")
  signal(error ("Unknown req `min-colors' with options `(88)'"))
  error("Unknown req `%S' with options `%S'" min-colors (88))
  face-spec-set-match-display(((min-colors 88) (class color)) #<frame F1 0x201a3600\ >)
  face-spec-choose((((... ...) (:foreground "red1")) ((...) (:foreground "red")) (t (:underline t))) #<frame F1 0x201a3600\ >)
  face-spec-set(ido-subdir (((... ...) (:foreground "red1")) ((...) (:foreground "red")) (t (:underline t))) #<frame F1 0x201a3600\ >)
  custom-declare-face(ido-subdir (((... ...) (:foreground "red1")) ((...) (:foreground "red")) (t (:underline t))) "Face used by ido for highlighting subdirs in the alternatives." :group ido)
  (defface ido-subdir (quote (... ... ...)) "Face used by ido for highlighting subdirs in the alternatives." :group (quote ido))
  eval-buffer(#<buffer  *load*<2>> nil "~/.emacs.d/site-lisp/ido/ido.el" nil t)
  load-with-code-conversion("~/.emacs.d/site-lisp/ido/ido.el" "~/.emacs.d/site-lisp/ido/ido.el" nil nil)
  load("~/.emacs.d/site-lisp/ido/ido.el" nil nil t)
  load-file("~/.emacs.d/site-lisp/ido/ido.el")
  eval-buffer(#<buffer  *load*> nil "~/.emacs" nil t)
  load-with-code-conversion("~/.emacs" "~/.emacs" t t)
  load("~/.emacs" t t)
  #[nil "^H\205\227^@   Æ=\203^Q^@Ç^HÈQ\2025^@  É=\203'^@ÊÇËÌ#\203#^@Í\2025^@Î\2025^@   Ï=\2031^@Ð\2025^@Ç^HÑQ^ZÒ^SÓ\nÒ\211#\210^KÒ=\203F^@Ë^S^K\203\210^@Ô^K!Õ\232\203\210^@Ö^K!\211^\×P^]Ø^M!\203d$
  command-line()
  normal-top-level()

I have the same problem. We're upgrading to RHEL5, so I assume we'll have emacs 21 for a long time. Luckily the EmacsWiki has a link to an older version. It's over a decade old, but it's better than nothing.

It seems to work fine, but some of the constants have different names. For example, I had set ido-default-file-method to selected-window, but the latter is named same-window in the older version of the code.