Index: cmake/modules/HandleLLVMOptions.cmake
===================================================================
--- cmake/modules/HandleLLVMOptions.cmake
+++ cmake/modules/HandleLLVMOptions.cmake
@@ -720,11 +720,13 @@
 add_definitions( -D__STDC_FORMAT_MACROS )
 add_definitions( -D__STDC_LIMIT_MACROS )
 
-# clang doesn't print colored diagnostics when invoked from Ninja
+# clang and gcc don't default-print colored diagnostics when invoked from Ninja.
 if (UNIX AND
-    CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND
-    CMAKE_GENERATOR STREQUAL "Ninja")
-  append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+    CMAKE_GENERATOR STREQUAL "Ninja" AND
+    (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
+     (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND
+      NOT (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.9))))
+  append("-fdiagnostics-color" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 endif()
 
 # lld doesn't print colored diagnostics when invoked from Ninja