diff --git a/Library/Homebrew/dev-cmd/tests.rb b/Library/Homebrew/dev-cmd/tests.rb
index 667676789d..f869f43afd 100644
--- a/Library/Homebrew/dev-cmd/tests.rb
+++ b/Library/Homebrew/dev-cmd/tests.rb
@@ -34,6 +34,8 @@ module Homebrew
     end
 
     HOMEBREW_LIBRARY_PATH.cd do
+      ENV.delete("HOMEBREW_COLOR")
+      ENV.delete("HOMEBREW_NO_COLOR")
       ENV.delete("HOMEBREW_VERBOSE")
       ENV.delete("VERBOSE")
       ENV.delete("HOMEBREW_CASK_OPTS")
diff --git a/Library/Homebrew/utils/tty.rb b/Library/Homebrew/utils/tty.rb
index eb6f02746f..fb53968c5f 100644
--- a/Library/Homebrew/utils/tty.rb
+++ b/Library/Homebrew/utils/tty.rb
@@ -61,7 +61,7 @@ module Tty
   end
 
   def to_s
-    if ENV["HOMEBREW_NO_COLOR"] || !$stdout.tty?
+    if !ENV["HOMEBREW_COLOR"] && (ENV["HOMEBREW_NO_COLOR"] || !$stdout.tty?)
       return ""
     end
     current_escape_sequence