Bug: Nothing but hex colors works

[lucassperez]

Describe the bug
Only hex codes in the form of #abcdef, #abc and #abcdef00 are working.

To Reproduce
I replaced my whole neovim configuration for this:

local lazypath = vim.fn.stdpath('data') .. '/lazy/lazy.nvim'

if not vim.loop.fs_stat(lazypath) then
  vim.fn.system({
    'git',
    'clone',
    '--filter=blob:none',
    'https://github.com/folke/lazy.nvim.git',
    '--branch=stable', -- latest stable release
    lazypath,
  })
end
vim.opt.rtp:prepend(lazypath)

local ok, lazy = pcall(require, 'lazy')
if not ok then
  vim.notify('Could not require lazy!', vim.log.levels.ERROR)
  vim.notify('Exiting from plugins/init.lua', vim.log.levels.ERROR)
  return
end

lazy.setup({
  {
    'NvChad/nvim-colorizer.lua',
    cmd = {
      'ColorizerToggle',
      'ColorizerAttachToBuffer',
      'ColorizerDetachFromBuffer',
      'ColorizerReloadAllBuffers',
    },
    config = function()
      vim.opt.termguicolors = true
      require('colorizer').setup({
        filetypes = { 'conf' },
        user_default_options = {
          -- foreground, background,  virtualtext
          mode = 'background',

          names = true,
          RGB = true, -- #RGB hex codes
          RRGGBB = true, -- #RRGGBB hex codes
          RRGGBBAA = true, -- #RRGGBBAA hex codes
          AARRGGBB = true, -- 0xAARRGGBB hex codes
          rgb_fn = true, -- CSS rgb() and rgba() functions
          hsl_fn = true, -- CSS hsl() and hsla() functions
          css = true, -- Enable all CSS features: rgb_fn, hsl_fn, names, RGB, RRGGBB
          css_fn = true, -- Enable all CSS *functions*: rgb_fn, hsl_fn
          -- Available methods are false / true / "normal" / "lsp" / "both"
          -- True is same as normal
          tailwind = true, -- Enable tailwind colors
          -- parsers can contain values used in |user_default_options|
          sass = { enable = true, parsers = { 'css' } }, -- Enable sass colors
          virtualtext = '■',
        },
      })
    end,
  },
})

Expected behavior
When I open a file with things like rgb(123456), I expected it to be colored.

Screenshots
If applicable, add screenshots to help explain your problem.

Operating System:
Fedora 39

Neovim Version:
0.9.5

Colorizer Version:
85855b3

Here is a screenshot of a file I'm editing: