Zenburn Treesitter highlights are missing/black

[jacksonludwig]

Describe the bug
When using zenburn with treesitter highlighting, there are missing/incorrect colors for operators, parenthesis, and some others.

Expected behavior
Operators and delimiters are highlighted thematically.

System
Vim or Neovim: Neovim
Vim or Neovim version:

NVIM v0.6.0-dev
Build type: Release
LuaJIT 2.1.0-beta3
Compiled by nixbld

Features: +acl +iconv +tui
See ":help feature-compile"

   system vimrc file: "$VIM/sysinit.vim"
  fall-back for $VIM: "
/nix/store/56jl11wa1sqxl582dsqjld9v4i8qbi6r-neovim-unwrapped-master/share/nvim
"

Run :checkhealth for more info

Minimal configuration file

lua << EOF

-- packer bootstrap
local fn = vim.fn
local install_path = fn.stdpath("data") .. "/site/pack/packer/start/packer.nvim"
local packer_bootstrap = nil
if fn.empty(fn.glob(install_path)) > 0 then
  packer_bootstrap = fn.system({
    "git",
    "clone",
    "--depth",
    "1",
    "https://github.com/wbthomason/packer.nvim",
    install_path,
  })
end

require("packer").startup(function(use)
  use({
    "nvim-treesitter/nvim-treesitter",
    config = function()
      require("nvim-treesitter.configs").setup({
        ensure_installed = {
          -- some langs here
          javascript,
        },
        highlight = {
          enable = true,
        },
      })
    end
  })

  use({
    "fnune-base16-vim",
    config = function()
      vim.cmd("colo base16-zenburn")
    end,
  })
end)

EOF