diff --git a/llvm/include/llvm/Support/raw_ostream.h b/llvm/include/llvm/Support/raw_ostream.h
--- a/llvm/include/llvm/Support/raw_ostream.h
+++ b/llvm/include/llvm/Support/raw_ostream.h
@@ -64,6 +64,7 @@
   /// for a \see write_impl() call to handle the data which has been put into
   /// this buffer.
   char *OutBufStart, *OutBufEnd, *OutBufCur;
+  bool ColorEnabled = false;
 
   enum class BufferKind {
     Unbuffered = 0,
@@ -272,19 +273,14 @@
   /// @returns itself so it can be used within << invocations
   virtual raw_ostream &changeColor(enum Colors Color,
                                    bool Bold = false,
-                                   bool BG = false) {
-    (void)Color;
-    (void)Bold;
-    (void)BG;
-    return *this;
-  }
+                                   bool BG = false);
 
   /// Resets the colors to terminal defaults. Call this when you are done
   /// outputting colored text, or before program exit.
-  virtual raw_ostream &resetColor() { return *this; }
+  virtual raw_ostream &resetColor();
 
   /// Reverses the foreground and background colors.
-  virtual raw_ostream &reverseColor() { return *this; }
+  virtual raw_ostream &reverseColor();
 
   /// This function determines if this stream is connected to a "tty" or
   /// "console" window. That is, the output would be displayed to the user
@@ -296,7 +292,7 @@
 
   // Enable or disable colors. Once disable_colors() is called,
   // changeColor() has no effect until enable_colors() is called.
-  virtual void enable_colors(bool /*enable*/) {}
+  virtual void enable_colors(bool enable) { ColorEnabled = enable; }
 
   //===--------------------------------------------------------------------===//
   // Subclass Interface
@@ -398,7 +394,6 @@
   int FD;
   bool ShouldClose;
   bool SupportsSeeking = false;
-  bool ColorEnabled = true;
 
 #ifdef _WIN32
   /// True if this fd refers to a Windows console device. Mintty and other
@@ -464,18 +459,10 @@
   /// to the offset specified from the beginning of the file.
   uint64_t seek(uint64_t off);
 
-  raw_ostream &changeColor(enum Colors colors, bool bold=false,
-                           bool bg=false) override;
-  raw_ostream &resetColor() override;
-
-  raw_ostream &reverseColor() override;
-
   bool is_displayed() const override;
 
   bool has_colors() const override;
 
-  void enable_colors(bool enable) override { ColorEnabled = enable; }
-
   std::error_code error() const { return EC; }
 
   /// Return the value of the flag in this raw_fd_ostream indicating whether an
diff --git a/llvm/lib/Support/raw_ostream.cpp b/llvm/lib/Support/raw_ostream.cpp
--- a/llvm/lib/Support/raw_ostream.cpp
+++ b/llvm/lib/Support/raw_ostream.cpp
@@ -499,6 +499,53 @@
   return write_padding<'\0'>(*this, NumZeros);
 }
 
+raw_ostream &raw_ostream::changeColor(enum Colors colors, bool bold,
+                                         bool bg) {
+  if (!ColorEnabled)
+    return *this;
+
+  if (sys::Process::ColorNeedsFlush())
+    flush();
+  const char *colorcode =
+      (colors == SAVEDCOLOR)
+          ? sys::Process::OutputBold(bg)
+          : sys::Process::OutputColor(static_cast<char>(colors), bold, bg);
+  if (colorcode) {
+    size_t len = strlen(colorcode);
+    write(colorcode, len);
+  }
+  return *this;
+}
+
+raw_ostream &raw_ostream::resetColor() {
+  if (!ColorEnabled)
+    return *this;
+
+  if (sys::Process::ColorNeedsFlush())
+    flush();
+  const char *colorcode = sys::Process::ResetColor();
+  if (colorcode) {
+    size_t len = strlen(colorcode);
+    write(colorcode, len);
+  }
+  return *this;
+}
+
+raw_ostream &raw_ostream::reverseColor() {
+  if (!ColorEnabled)
+    return *this;
+
+  if (sys::Process::ColorNeedsFlush())
+    flush();
+  const char *colorcode = sys::Process::OutputReverse();
+  if (colorcode) {
+    size_t len = strlen(colorcode);
+    write(colorcode, len);
+  }
+  return *this;
+}
+
+
 void raw_ostream::anchor() {}
 
 //===----------------------------------------------------------------------===//
@@ -589,6 +636,9 @@
       ::GetFileType((HANDLE)::_get_osfhandle(fd)) == FILE_TYPE_CHAR;
 #endif
 
+  // Enable color support.
+  enable_colors(true);
+
   // Get the starting position.
   off_t loc = ::lseek(FD, 0, SEEK_CUR);
 #ifdef _WIN32
@@ -798,58 +848,6 @@
 #endif
 }
 
-raw_ostream &raw_fd_ostream::changeColor(enum Colors colors, bool bold,
-                                         bool bg) {
-  if (!ColorEnabled)
-    return *this;
-
-  if (sys::Process::ColorNeedsFlush())
-    flush();
-  const char *colorcode =
-      (colors == SAVEDCOLOR)
-          ? sys::Process::OutputBold(bg)
-          : sys::Process::OutputColor(static_cast<char>(colors), bold, bg);
-  if (colorcode) {
-    size_t len = strlen(colorcode);
-    write(colorcode, len);
-    // don't account colors towards output characters
-    pos -= len;
-  }
-  return *this;
-}
-
-raw_ostream &raw_fd_ostream::resetColor() {
-  if (!ColorEnabled)
-    return *this;
-
-  if (sys::Process::ColorNeedsFlush())
-    flush();
-  const char *colorcode = sys::Process::ResetColor();
-  if (colorcode) {
-    size_t len = strlen(colorcode);
-    write(colorcode, len);
-    // don't account colors towards output characters
-    pos -= len;
-  }
-  return *this;
-}
-
-raw_ostream &raw_fd_ostream::reverseColor() {
-  if (!ColorEnabled)
-    return *this;
-
-  if (sys::Process::ColorNeedsFlush())
-    flush();
-  const char *colorcode = sys::Process::OutputReverse();
-  if (colorcode) {
-    size_t len = strlen(colorcode);
-    write(colorcode, len);
-    // don't account colors towards output characters
-    pos -= len;
-  }
-  return *this;
-}
-
 bool raw_fd_ostream::is_displayed() const {
   return sys::Process::FileDescriptorIsDisplayed(FD);
 }
diff --git a/llvm/unittests/Support/raw_ostream_test.cpp b/llvm/unittests/Support/raw_ostream_test.cpp
--- a/llvm/unittests/Support/raw_ostream_test.cpp
+++ b/llvm/unittests/Support/raw_ostream_test.cpp
@@ -350,6 +350,22 @@
             format_bytes_with_ascii_str(B.take_front(12), 0, 7, 1));
 }
 
+TEST(raw_ostreamTest, colors) {
+  {
+    std::string S;
+    raw_string_ostream Sos(S);
+    Sos.changeColor(raw_ostream::YELLOW);
+    EXPECT_TRUE(Sos.str().empty());
+  }
+  {
+    std::string S;
+    raw_string_ostream Sos(S);
+    Sos.enable_colors(true);
+    Sos.changeColor(raw_ostream::YELLOW);
+    EXPECT_FALSE(Sos.str().empty());
+  }
+}
+
 TEST(raw_fd_ostreamTest, multiple_raw_fd_ostream_to_stdout) {
   std::error_code EC;