Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -1353,8 +1353,11 @@
   Flags<[CC1Option]>, MetaVarName<"<version>">, Values<"<major>.<minor>,latest">,
   HelpText<"Attempt to match the ABI of Clang <version>">;
 def fclasspath_EQ : Joined<["-"], "fclasspath=">, Group<f_Group>;
-defm color_diagnostics : OptInCC1FFlag<"color-diagnostics", "Enable", "Disable", " colors in diagnostics",
-  [CoreOption, FlangOption]>;
+def fcolor_diagnostics : Flag<["-"], "fcolor-diagnostics">, Group<f_Group>,
+  Flags<[CoreOption, CC1Option, FlangOption, FC1Option]>,
+  HelpText<"Enable colors in diagnostics">;
+def fno_color_diagnostics : Flag<["-"], "fno-color-diagnostics">, Group<f_Group>,
+  Flags<[CoreOption, FlangOption]>, HelpText<"Disable colors in diagnostics">;
 def : Flag<["-"], "fdiagnostics-color">, Group<f_Group>, Flags<[CoreOption]>, Alias<fcolor_diagnostics>;
 def : Flag<["-"], "fno-diagnostics-color">, Group<f_Group>, Flags<[CoreOption]>, Alias<fno_color_diagnostics>;
 def fdiagnostics_color_EQ : Joined<["-"], "fdiagnostics-color=">, Group<f_Group>;
Index: clang/lib/Driver/ToolChains/Flang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Flang.cpp
+++ clang/lib/Driver/ToolChains/Flang.cpp
@@ -57,6 +57,7 @@
   const llvm::Triple &Triple = TC.getEffectiveTriple();
   const std::string &TripleStr = Triple.getTriple();
 
+  const Driver &D = TC.getDriver();
   ArgStringList CmdArgs;
 
   // Invoke ourselves in -fc1 mode.
@@ -100,6 +101,12 @@
 
   AddFortranDialectOptions(Args, CmdArgs);
 
+  // Silence the warning of argument unused.
+  Args.getLastArg(options::OPT_fcolor_diagnostics,
+                  options::OPT_fno_color_diagnostics);
+  if (D.getDiags().getDiagnosticOptions().ShowColors)
+    CmdArgs.push_back("-fcolor-diagnostics");
+
   // Add other compile options
   AddOtherOptions(Args, CmdArgs);
 
@@ -128,7 +135,6 @@
   assert(Input.isFilename() && "Invalid input.");
   CmdArgs.push_back(Input.getFilename());
 
-  const auto& D = C.getDriver();
   // TODO: Replace flang-new with flang once the new driver replaces the
   // throwaway driver
   const char *Exec = Args.MakeArgString(D.GetProgramPath("flang-new", TC));
Index: flang/include/flang/Frontend/CompilerInvocation.h
===================================================================
--- flang/include/flang/Frontend/CompilerInvocation.h
+++ flang/include/flang/Frontend/CompilerInvocation.h
@@ -30,8 +30,7 @@
 /// When errors are encountered, return false and, if Diags is non-null,
 /// report the error(s).
 bool parseDiagnosticArgs(clang::DiagnosticOptions &opts,
-                         llvm::opt::ArgList &args,
-                         bool defaultDiagColor = true);
+                         llvm::opt::ArgList &args);
 
 class CompilerInvocationBase {
 public:
Index: flang/include/flang/Frontend/FrontendOptions.h
===================================================================
--- flang/include/flang/Frontend/FrontendOptions.h
+++ flang/include/flang/Frontend/FrontendOptions.h
@@ -214,7 +214,7 @@
 struct FrontendOptions {
   FrontendOptions()
       : showHelp(false), showVersion(false), instrumentedParse(false),
-        needProvenanceRangeToCharBlockMappings(false) {}
+        showColors(false), needProvenanceRangeToCharBlockMappings(false) {}
 
   /// Show the -help text.
   unsigned showHelp : 1;
@@ -225,6 +225,9 @@
   /// Instrument the parse to get a more verbose log
   unsigned instrumentedParse : 1;
 
+  /// Enable color diagnostics.
+  unsigned showColors : 1;
+
   /// Enable Provenance to character-stream mapping. Allows e.g. IDEs to find
   /// symbols based on source-code location. This is not needed in regular
   /// compilation.
Index: flang/lib/Frontend/CompilerInvocation.cpp
===================================================================
--- flang/lib/Frontend/CompilerInvocation.cpp
+++ flang/lib/Frontend/CompilerInvocation.cpp
@@ -53,10 +53,11 @@
 //===----------------------------------------------------------------------===//
 // Deserialization (from args)
 //===----------------------------------------------------------------------===//
-static bool parseShowColorsArgs(
-    const llvm::opt::ArgList &args, bool defaultColor) {
-  // Color diagnostics default to auto ("on" if terminal supports) in the driver
-  // but default to off in cc1, needing an explicit OPT_fdiagnostics_color.
+static bool parseShowColorsArgs(const llvm::opt::ArgList &args,
+                                bool defaultColor = true) {
+  // Color diagnostics default to auto ("on" if terminal supports) in the
+  // compiler driver `flang-new` but default to off in the frontend driver
+  // `flang-new -fc1`, needing an explicit OPT_fdiagnostics_color.
   // Support both clang's -f[no-]color-diagnostics and gcc's
   // -f[no-]diagnostics-colors[=never|always|auto].
   enum {
@@ -88,9 +89,8 @@
 }
 
 bool Fortran::frontend::parseDiagnosticArgs(clang::DiagnosticOptions &opts,
-                                            llvm::opt::ArgList &args,
-                                            bool defaultDiagColor) {
-  opts.ShowColors = parseShowColorsArgs(args, defaultDiagColor);
+                                            llvm::opt::ArgList &args) {
+  opts.ShowColors = parseShowColorsArgs(args);
 
   return true;
 }
@@ -497,6 +497,10 @@
     }
   }
 
+  // Default to off for `flang-new -fc1`.
+  res.getFrontendOpts().showColors =
+      parseShowColorsArgs(args, /*defaultDiagColor=*/false);
+
   return diags.getNumErrors() == numErrorsBefore;
 }
 
Index: flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
===================================================================
--- flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
+++ flang/lib/FrontendTool/ExecuteCompilerInvocation.cpp
@@ -158,6 +158,9 @@
     return false;
   }
 
+  // Honor color diagnostics.
+  flang->getDiagnosticOpts().ShowColors = flang->getFrontendOpts().showColors;
+
   // Create and execute the frontend action.
   std::unique_ptr<FrontendAction> act(createFrontendAction(*flang));
   if (!act)
Index: flang/test/Driver/driver-help.f90
===================================================================
--- flang/test/Driver/driver-help.f90
+++ flang/test/Driver/driver-help.f90
@@ -83,6 +83,7 @@
 ! HELP-FC1-NEXT: -falternative-parameter-statement
 ! HELP-FC1-NEXT: Enable the old style PARAMETER statement
 ! HELP-FC1-NEXT: -fbackslash            Specify that backslash in string introduces an escape character
+! HELP-FC1-NEXT: -fcolor-diagnostics     Enable colors in diagnostics
 ! HELP-FC1-NEXT: -fdebug-dump-all       Dump symbols and the parse tree after the semantic checks
 ! HELP-FC1-NEXT: -fdebug-dump-parse-tree-no-sema
 ! HELP-FC1-NEXT:                        Dump the parse tree (skips the semantic checks)