feat(helpers/_error): add red color

helpers/_error.function.fish

@@ -3,6 +3,6 @@ function _error --description 'Call with `_error <msg> <var1> <var2> … <var_n>
     set out $out {$i}="$$i"
   end
 
-  echo $argv[1] '('(string join ', ' $out)')'
+  begin; echo set_color brred; echo -n $argv[1]; set_color red; echo ' ('(string join ', ' $out)')'; set_color normal; end 1>&2
   exit 1
 end