Bugfix in color conversion

color_names.ml

@@ -107,6 +107,7 @@ let compress = function
   | Hexcolor "dda0dd"               -> Ident "plum"
   | Ident "powderblue"              -> Hexcolor "b0e0e6"
   | Hexcolor "800080"               -> Ident "purple"
+  | Hexcolor "f00"                  -> Ident "red"
   | Ident "rosybrown"               -> Hexcolor "bc8f8f"
   | Ident "royalblue"               -> Hexcolor "4169e1"
   | Ident "saddlebrown"             -> Hexcolor "8b4513"

simple.ml

@@ -16,7 +16,7 @@ let rec shorten_expr = function
   (* #aabbcc -> #abc *)
   | Hexcolor h when Str.string_match hex6 h 0 ->
     let gr n = Str.matched_group n h in
-    Hexcolor (gr 1 ^ gr 2 ^ gr 3)
+    shorten_expr (Hexcolor (gr 1 ^ gr 2 ^ gr 3))
 
   (* rgb(r,g,b) -> #rrggbb *)
   | Function ("rgb", Nary (",", [r; g; b]))