diff --git a/CHANGELOG.md b/CHANGELOG.md
index d74302a2..21c81605 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 Master
 ===
 
+* Fix buggy color renaming in built-in CSS minifier. #576
 * Fix Sass/Scss filter in Slim templates
 * Added SMACSS template
 * Give file metadata (such as frontmatter) precedence over path meta. #552
diff --git a/middleman-more/features/minify_css.feature b/middleman-more/features/minify_css.feature
index 9a379c91..eb39da6b 100644
--- a/middleman-more/features/minify_css.feature
+++ b/middleman-more/features/minify_css.feature
@@ -23,6 +23,8 @@ Feature: Minify CSS
     And I should see "only screen and (device-width"
     When I go to "/more-css/site.css"
     Then I should see "1" lines
+    When I go to "/stylesheets/report.css"
+    Then I should see "p{border:1px solid #ff6600}"
     
   Scenario: Rendering external css with passthrough compressor
     Given a fixture app "passthrough-app"
diff --git a/middleman-more/fixtures/minify-css-app/source/stylesheets/report.css b/middleman-more/fixtures/minify-css-app/source/stylesheets/report.css
new file mode 100644
index 00000000..47b7bef1
--- /dev/null
+++ b/middleman-more/fixtures/minify-css-app/source/stylesheets/report.css
@@ -0,0 +1 @@
+p{border: 1px solid #ff6600;}
\ No newline at end of file
diff --git a/middleman-more/lib/middleman-more/extensions/minify_css/rainpress.rb b/middleman-more/lib/middleman-more/extensions/minify_css/rainpress.rb
index a2db14bc..c355e0c0 100644
--- a/middleman-more/lib/middleman-more/extensions/minify_css/rainpress.rb
+++ b/middleman-more/lib/middleman-more/extensions/minify_css/rainpress.rb
@@ -25,7 +25,7 @@ class Rainpress
       :comments => true,
       :newlines => true,
       :spaces   => true,
-      :colors   => true,
+      :colors   => false,
       :misc     => true
     }
     @opts.merge! opts