Try:
M-x color-theme-select
Move point (the cursor) to first line showing:
[Reset]
and press 'Enter' (return).
Alternatively, to get back to the Emacs default themes, also try:
M-x color-theme-emacs-21
or
M-x color-theme-standard
However, from your question it's not clear which theme you initially started with. For example, if you simply been using the default theme provided in the color-theme quickstart when you first (manually) installed color-theme then do this:
M-x color-theme-hober
or whatever you had specified in your .emacs file (if applicable).
You might want to have a look at Emacs W32. Has some nice customizations for windows.
As for getting color theme working... I won't try to convert things to your current install, seems a few things are off there (file should just be .emacs - not User.emacs, same for .emacs.d directory). Instead I'll just tell you how I have things setup, shouldn't be too hard to translate if you want to keep your current config.
I find it easiest to just create a C:\home directory and set a HOME enviornment variable to point to that directory. Place your .emacs file in there. A .emacs.d directory will be created. I also like to create a directory named emacs_site_lisp in the home folder; C:\home\emacs_site_lisp. I place any and all packages or files under there for easy reference.
Put the color-theme directory in the emacs_site_lisp folder.
Then in my .emacs I have:
(setq load-path (append load-path (list "~/emacs_site_lisp")))
(setq load-path (append load-path (list "~/emacs_site_lisp/color-theme-6.6.0")))
(require 'color-theme)
(color-theme-hober)
Note that ~ references your home directory if not familiar with *nix.
That should work as a minimal .emacs - odds are you'll have a lot more stuff in there soon as you try different things out & tweak different settings, plenty of example .emacs to be found... just search on google: filetype:emacs
Good Luck.
Best Answer
There isn't the concept of a current theme, and indeed, multiple themes can be applied in sequence to additively define the set of active faces. Support for theming was added into the latest Emacs versions (see
M-x customize-theme), and there's still the option to "Select more than one theme at a time".In short, when you activate a theme, you're not switching to that theme, but rather applying the changes specified in the theme to the faces and variables it lists.
All customizations which aren't explicitly placed in a named theme are actually put into the hidden user theme, so there's always at least one active theme. The other currently enabled themes are listed in the variable
custom-enabled-themes.