diff --git a/shellcheck.hs b/shellcheck.hs
index a11d8f4..9bebd34 100644
--- a/shellcheck.hs
+++ b/shellcheck.hs
@@ -75,7 +75,8 @@ options = [
     Option "f" ["format"]
         (ReqArg (Flag "format") "FORMAT") "output format",
     Option "C" ["color"]
-        (ReqArg (Flag "color") "WHEN") "Set use of color (auto, always, never)",
+        (OptArg (maybe (Flag "color" "always") (Flag "color")) "WHEN")
+        "Set use of color (auto, always, never)",
     Option "s" ["shell"]
         (ReqArg (Flag "shell") "SHELLNAME") "Specify dialect (sh,bash,dash,ksh)",
     Option "x" ["external-sources"]