diff --git a/hledger-lib/Hledger/Utils/Debug.hs b/hledger-lib/Hledger/Utils/Debug.hs
index a129084fb..90b3234df 100644
--- a/hledger-lib/Hledger/Utils/Debug.hs
+++ b/hledger-lib/Hledger/Utils/Debug.hs
@@ -208,20 +208,25 @@ useColorOnHandle h = unsafePerformIO $ do
 -- (When running code in GHCI, this module must be reloaded to see a change.)
 -- {-# OPTIONS_GHC -fno-cse #-}
 -- {-# NOINLINE colorOption #-}
+-- Keep synced with color/colour flag definition in hledger:CliOptions
 colorOption :: String
 colorOption = 
   -- similar to debugLevel
   let args = unsafePerformIO getArgs in
   case snd $ break (=="--color") args of
+    -- --color ARG
     "--color":v:_ -> v
     _ ->
       case take 1 $ filter ("--color=" `isPrefixOf`) args of
+        -- --color=ARG
         ['-':'-':'c':'o':'l':'o':'r':'=':v] -> v
         _ ->
           case snd $ break (=="--colour") args of
+            -- --colour ARG
             "--colour":v:_ -> v
             _ ->
               case take 1 $ filter ("--colour=" `isPrefixOf`) args of
+                -- --colour=ARG
                 ['-':'-':'c':'o':'l':'o':'u':'r':'=':v] -> v
                 _ -> ""
 
diff --git a/hledger/Hledger/Cli/CliOptions.hs b/hledger/Hledger/Cli/CliOptions.hs
index b482c24e9..bb54cf619 100644
--- a/hledger/Hledger/Cli/CliOptions.hs
+++ b/hledger/Hledger/Cli/CliOptions.hs
@@ -190,7 +190,8 @@ reportflags = [
    ])
 
   -- general output-related
-
+  
+  -- This has special support in hledger-lib:colorOption, keep synced
  ,flagReq  ["color","colour"] (\s opts -> Right $ setopt "color" s opts) "WHEN"
    (unlines
      ["Should color-supporting commands use ANSI color codes in text output."
@@ -228,6 +229,7 @@ outputFormatFlag fmts = flagReq
   ["output-format","O"] (\s opts -> Right $ setopt "output-format" s opts) "FMT"
   ("select the output format. Supported formats:\n" ++ intercalate ", " fmts ++ ".")
 
+-- This has special support in hledger-lib:outputFileOption, keep synced
 outputFileFlag :: Flag RawOpts
 outputFileFlag = flagReq
   ["output-file","o"] (\s opts -> Right $ setopt "output-file" s opts) "FILE"