--- ccache.c
+++ ccache.c
@@ -1065,6 +1065,24 @@
 }
 
 /*
+ * Note that these compiler checks are unreliable, so nothing should hard-depend on them.
+ */
+
+static bool compiler_is_clang()
+{
+    const char* name = strrchr( orig_args->argv[ 0 ], '/' );
+    name = name ? name + 1 : orig_args->argv[ 0 ];
+    return strstr( name, "clang" ) != NULL;
+}
+
+static bool compiler_is_gcc()
+{
+    const char* name = strrchr(orig_args->argv[ 0 ], '/' );
+    name = name ? name + 1 : orig_args->argv[ 0 ];
+    return strstr(name, "gcc") != NULL || strstr(name, "g++") != NULL;
+}
+
+/*
  * Update a hash sum with information common for the direct and preprocessor
  * modes.
  */
@@ -1128,6 +1146,15 @@
 		}
 		free(p);
 	}
+
+        /* Possibly hash GCC_COLORS (for color diagnostics). */
+        if (compiler_is_gcc()) {
+            const char* gcc_colors = getenv("GCC_COLORS");
+            if (gcc_colors != NULL) {
+                hash_delimiter(hash,"gcccolors");
+                hash_string(hash, gcc_colors);
+            }
+        }
 }
 
 /*
@@ -1626,6 +1653,13 @@
 	       || str_eq(get_extension(path), ".pth");
 }
 
+static bool color_output_possible()
+{
+    const char* term_env = getenv("TERM");
+
+    return term_env && strcasecmp(term_env, "DUMB") != 0;
+}
+
 /*
  * Process the compiler options into options suitable for passing to the
  * preprocessor and the real compiler. The preprocessor options don't include
@@ -1654,6 +1688,7 @@
 	int argc;
 	char **argv;
 	bool result = true;
+	bool found_color_diagnostics = false;
 
 	expanded_args = args_copy(args);
 	stripped_args = args_init(0, NULL);
@@ -2010,6 +2045,27 @@
 			free(arg);
 		}
 
+		if (str_eq(argv[i], "-fcolor-diagnostics")
+		    || str_eq(argv[i], "-fno-color-diagnostics")
+		    || str_eq(argv[i], "-fdiagnostics-color")
+		    || str_eq(argv[i], "-fdiagnostics-color=always")
+		    || str_eq(argv[i], "-fno-diagnostics-color")
+		    || str_eq(argv[i], "-fdiagnostics-color=never")) {
+		        args_add(stripped_args, argv[i]);
+		        found_color_diagnostics = true;
+		        continue;
+		}
+		if (str_eq(argv[i], "-fdiagnostics-color=auto")) {
+
+			/* auto means to use colours only when standard error is a terminal */
+			if (color_output_possible()) {
+				/* Since the condition is verified, we force the colour output */
+				args_add(stripped_args, "-fdiagnostics-color");
+				found_color_diagnostics = true;
+			}
+		    continue;
+		}
+
 		/*
 		 * Options taking an argument that we may want to rewrite to relative paths
 		 * to get better hit rate. A secondary effect is that paths in the standard
@@ -2298,6 +2354,28 @@
 		args_add(cpp_args, explicit_language);
 	}
 
+        /*
+         * Since output is redirected, compilers will not color their output by default,
+         * so force it explicitly if it would be otherwise done.
+         */
+        if (!found_color_diagnostics && color_output_possible()) {
+            if (compiler_is_clang()) {
+                args_add(stripped_args, "-fcolor-diagnostics");
+                cc_log("Automatically enabling colors");
+            } else if (compiler_is_gcc()) {
+                /*
+                 * GCC has colour support since 4.9. Adding the option to an
+                 * earlier version of GCC will make the compiler fail.
+                 * This test enables colours if GCC_COLORS is present in the 
+                 * environment, but does not check if diagnostics-color is available.
+                 */
+                if (getenv("GCC_COLORS") != NULL && getenv("GCC_COLORS")[ 0 ] != '\0') {
+                    args_add(stripped_args, "-fdiagnostics-color");
+                    cc_log("Automatically enabling colors");
+                }
+            }
+        }
+
 	/*
 	 * Add flags for dependency generation only to the preprocessor command line.
 	 */