```ruby
# Theme controller
class ThemeController < ApplicationController
  # callbacks
  before_action :login_required, except: MO.themes + [
    :color_themes,
  ]
  before_action :disable_link_prefetching

  # Displays info on color themes.
  def color_themes # :nologin:
  end
end
```

Document public actions of ThemeController
user
```ruby
# Theme controller
# Shows information about available user color themes.
#
#  ==== Public Actions =====
#  color_themes::       Show general information about color themes
#  Agaricus, etc.::     Show sample page, explaining color derivation.
#
class ThemeController < ApplicationController
  # callbacks
  before_action :login_required, except: MO.themes + [
    :color_themes,
  ]
  before_action :disable_link_prefetching

  # Show general information on color themes
  def color_themes # :nologin:
  end

  # Individual theme actions. Each shows a sample page in that theme,
  # explaining the colors for that theme.
  # These actions are not defined here, but rather are automagically created
  # if there's a view template corresponding to the theme.
end
```
assistant