chore: change warning message

lib.nix

@@ -18,8 +18,9 @@ let
   inherit (builtins) isString isFloat isInt isBool isList isAttrs isNull isPath;
   inherit (builtins) concatStringsSep filter mapAttrs attrValues;
 
-  # Source: https://github.com/NixOS/nixpkgs/blob/12f0044f83517e653d0b4fe12a99d162d9407437/lib/trivial.nix#L357
-  warn = msg: builtins.trace "[1;31mwarning: ${msg}[0m";
+  error = message: throw "[nix2lua] ${message}";
+
+  warn = msg: builtins.trace "[nix2lua] warning: ${msg}";
 
   mkLuaRaw = raw: { _type = "raw"; inherit raw; };
   isLuaRaw = expr: getType expr == "raw";
@@ -75,8 +76,6 @@ let
   validString = expr:
     if isString expr || isPath expr then toString expr
     else error "Value '${toString expr}' is not a valid string";
-
-  error = message: throw "[nix2lua] ${message}";
 in
 {
   inherit toLua;