in a Razor file, in Dark mode, @ is black on black

Using the Dark themes from this Swag  (except 'Dark (Visual Studio 2019)') , a cshtml or Razor file is unusable. The "@" (an important symbol in Razor) is black on a nearly-black background.

Previously reported to https://developercommunity.visualstudio.com/t/in-cshtml-file-in-Dark-mode--is-black/10020011, but that is apparently the wrong channel.

