color theme of floating window look different with others

[MontiL]

I am trying to use cmp-nvim-lsp-signature-help
I found the theme of floating window are different
Not sure if I missed something

my config:

-- reference:
-- https://github.com/hrsh7th/nvim-cmp#setup

local status_ok, cmp = pcall(require, "cmp")
if not status_ok then
  return
end

--[[ local check_backspace = function() ]]
--[[   local col = vim.fn.col(".") - 1 ]]
--[[   return col == 0 or vim.fn.getline("."):sub(col, col):match("%s") ]]
--[[ end ]]

--   פּ ﯟ   some other good icons
local kind_icons = {
  Text = "",
  Method = "m",
  Function = "",
  Constructor = "",
  Field = "",
  Variable = "",
  Class = "",
  Interface = "",
  Module = "",
  Property = "",
  Unit = "",
  Value = "",
  Enum = "",
  Keyword = "",
  Snippet = "",
  Color = "",
  File = "",
  Reference = "",
  Folder = "",
  EnumMember = "",
  Constant = "",
  Struct = "",
  Event = "",
  Operator = "",
  TypeParameter = "",
}
--- find more here: https://www.nerdfonts.com/cheat-sheet
--[[]]

cmp.setup({
  snippet = {
    expand = function(args)
      --[[ vim.fn["vsnip#anonymous"](args.body) -- For `vsnip` users. ]]
      require('luasnip').lsp_expand(args.body) -- For `luasnip` users.
    end,
  },
  window = {
    completion = cmp.config.window.bordered(),
    documentation = cmp.config.window.bordered(),
  },
  mapping = cmp.mapping.preset.insert({
    ["<Tab>"] = cmp.mapping.select_next_item(),
    ["<S-Tab>"] = cmp.mapping.select_prev_item(),
    ["<C-j>"] = cmp.mapping.select_next_item(),
    ["<C-k>"] = cmp.mapping.select_prev_item(),
    ['<C-b>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    --[[ ['<C-Space>'] = cmp.mapping.complete(), ]]
    ['<C-e>'] = cmp.mapping.abort(),
    -- Accept currently selected item. If none selected, `select` first item.
    -- Set `select` to `false` to only confirm explicitly selected items.
    ["<CR>"] = cmp.mapping.confirm({ select = true }),
  }),
  sources = cmp.config.sources({
    {
      name = "buffer",
      option = {
        get_bufnrs = function()
          local buf = vim.api.nvim_get_current_buf()
          local byte_size = vim.api.nvim_buf_get_offset(buf, vim.api.nvim_buf_line_count(buf))
          if byte_size > 1024 * 1024 then -- 1 Megabyte max
            return {}
          end
          return { buf }
        end,
      },
    },
    { name = "luasnip" }, -- For luasnip users.
    { name = "nvim_lsp" },
    { name = "nvim_lua" },
    --[[ { name = "vsnip" }, -- For vsnip users. ]]
    -- { name = "ultisnips" }, -- For ultisnips users.
    -- { name = "snippy" }, -- For snippy users.
    { name = "buffer" },
    { name = "path" },
    { name = "emoji" },
    { name = 'nvim_lsp_signature_help' }
  }),
  formatting = {
    fields = { "kind", "abbr", "menu" },
    format = function(entry, vim_item)
      -- Kind icons
      vim_item.kind = string.format("%s", kind_icons[vim_item.kind])
      -- vim_item.kind = string.format('%s %s', kind_icons[vim_item.kind], vim_item.kind) -- This concatonates the icons with the name of the item kind

      vim_item.menu = ({
        luasnip = "[Snippet]",
        --[[ vsnip = "[Snippet]", ]]
        nvim_lsp = "[LSP]",
        nvim_lua = "[NVIM_LUA]",
        buffer = "[Buffer]",
        path = "[Path]",
        emoji = "[Emoji]",
      })[entry.source.name]

      local source_mapping = {
        luasnip = "[Snippet]",
        nvim_lsp = "[LSP]",
        buffer = "[Buffer]",
        nvim_lua = "[Lua]",
        --[[ vsnip = "[Snippet]", ]]
        path = "[Path]",
        emoji = "[Emoji]",
      }

      local menu = source_mapping[entry.source.name]
      vim_item.menu = menu

      return vim_item
    end,
  },
  confirm_opts = {
    behavior = cmp.ConfirmBehavior.Replace,
    select = false,
  },
  experimental = {
    ghost_text = false,
    native_menu = false,
  },
})

-- Use buffer source for `/` and `?` (if you enabled `native_menu`, this won't work anymore).
cmp.setup.cmdline({ '/', '?' }, {
  mapping = cmp.mapping.preset.cmdline(),
  sources = {
    { name = 'buffer' }
  }
})

-- Use cmdline & path source for ':' (if you enabled `native_menu`, this won't work anymore).
cmp.setup.cmdline(':', {
  mapping = cmp.mapping.preset.cmdline(),
  sources = cmp.config.sources({
    { name = 'path' }
  }, {
    { name = 'cmdline' }
  })
})

--- https://github.com/windwp/nvim-autopairs#you-need-to-add-mapping-cr-on-nvim-cmp-setupcheck-readmemd-on-nvim-cmp-repo

local snip_status_ok, luasnip = pcall(require, "luasnip")
if not snip_status_ok then
  return
end

require("luasnip/loaders/from_vscode").lazy_load()

[Tom-Hadean]

The theme on lsp.buf.signature_help matches my theme well:

However the theme from cmp-nvim-lsp-signature-help is somehow not even respecting my font configuration of no italics. The theme is also very bare.

I'm on nvim 0.9.4.

[Tom-Hadean]

I've found the source of the unwanted italics - source._signature_label injecting *** markdown tags. I'm unsure about the rest of the theme issue.