diff --git a/lib/rbs/cli.rb b/lib/rbs/cli.rb
index 1ce7f898d..913ff3395 100644
--- a/lib/rbs/cli.rb
+++ b/lib/rbs/cli.rb
@@ -6,6 +6,8 @@
 require "abbrev"
 require "stringio"
 
+require_relative 'cli/colored_io'
+
 module RBS
   class CLI
     class LibraryOptions
diff --git a/lib/rbs/collection/colored_io.rb b/lib/rbs/cli/colored_io.rb
similarity index 94%
rename from lib/rbs/collection/colored_io.rb
rename to lib/rbs/cli/colored_io.rb
index 4406db88d..53cf3a7b7 100644
--- a/lib/rbs/collection/colored_io.rb
+++ b/lib/rbs/cli/colored_io.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 module RBS
-  module Collection
+  class CLI
     class ColoredIO
       attr_reader :stdout
 
@@ -36,6 +36,5 @@ def are_colors_disabled?
         !ENV['NO_COLOR'].nil? && !ENV.fetch('NO_COLOR', '').empty?
       end
     end
-    private_constant :ColoredIO
   end
 end
diff --git a/lib/rbs/collection.rb b/lib/rbs/collection.rb
index d15cc5e91..56f208221 100644
--- a/lib/rbs/collection.rb
+++ b/lib/rbs/collection.rb
@@ -3,7 +3,6 @@
 require 'yaml'
 require 'bundler'
 
-require_relative './collection/colored_io'
 require_relative './collection/sources'
 require_relative './collection/config'
 require_relative './collection/config/lockfile'
diff --git a/lib/rbs/collection/installer.rb b/lib/rbs/collection/installer.rb
index bba802390..95c29ec99 100644
--- a/lib/rbs/collection/installer.rb
+++ b/lib/rbs/collection/installer.rb
@@ -25,7 +25,7 @@ def install_from_lockfile
             stdout: stdout
           )
         end
-        ColoredIO.new(stdout: stdout).puts_green("It's done! #{selected.size} gems' RBSs now installed.")
+        CLI::ColoredIO.new(stdout: stdout).puts_green("It's done! #{selected.size} gems' RBSs now installed.")
       end
     end
   end
diff --git a/lib/rbs/collection/sources/git.rb b/lib/rbs/collection/sources/git.rb
index 684b60d91..95a19fd63 100644
--- a/lib/rbs/collection/sources/git.rb
+++ b/lib/rbs/collection/sources/git.rb
@@ -45,7 +45,7 @@ def install(dest:, name:, version:, stdout:)
 
           gem_dir = dest.join(name, version)
 
-          colored_io = ColoredIO.new(stdout: stdout)
+          colored_io = CLI::ColoredIO.new(stdout: stdout)
 
           case
           when gem_dir.symlink?
diff --git a/lib/rbs/collection/sources/local.rb b/lib/rbs/collection/sources/local.rb
index c6567e335..1afde557d 100644
--- a/lib/rbs/collection/sources/local.rb
+++ b/lib/rbs/collection/sources/local.rb
@@ -33,7 +33,7 @@ def install(dest:, name:, version:, stdout:)
           from = @full_path.join(name, version)
           gem_dir = dest.join(name, version)
 
-          colored_io = ColoredIO.new(stdout: stdout)
+          colored_io = CLI::ColoredIO.new(stdout: stdout)
 
           case
           when gem_dir.symlink? && gem_dir.readlink == from
diff --git a/sig/cli.rbs b/sig/cli.rbs
index 88e1e1521..5728511c6 100644
--- a/sig/cli.rbs
+++ b/sig/cli.rbs
@@ -15,6 +15,17 @@ module RBS
       def setup_library_options: (OptionParser) -> OptionParser
     end
 
+    class ColoredIO
+      attr_reader stdout: CLI::_IO
+      def initialize: (stdout: CLI::_IO) -> void
+      def puts_green: (String) -> void
+      def puts: (String) -> void
+
+      private def can_display_colors?: () -> bool
+      private def are_colors_supported?: () -> bool
+      private def are_colors_disabled?: () -> bool
+    end
+
     interface _IO
       def puts: (*untyped) -> void
 
diff --git a/sig/collection/colored_io.rbs b/sig/collection/colored_io.rbs
deleted file mode 100644
index 9a3b5977c..000000000
--- a/sig/collection/colored_io.rbs
+++ /dev/null
@@ -1,14 +0,0 @@
-module RBS
-  module Collection
-    class ColoredIO
-      attr_reader stdout: CLI::_IO
-      def initialize: (stdout: CLI::_IO) -> void
-      def puts_green: (String) -> void
-      def puts: (String) -> void
-
-      private def can_display_colors?: () -> bool
-      private def are_colors_supported?: () -> bool
-      private def are_colors_disabled?: () -> bool
-    end
-  end
-end