Warning blending not working

[Tyan-0978]

The color blending does not seem to work after exceeding colorcolumn.

This is a part of my config. I installed it using vim-plug.

require('deadcolumn').setup({
    blending = {
        threshold = 0.8,
    },
    warning = {
        alpha = 0.5,
    }
})

With warning.alpha = 0.5 or below:

With warning.alpha = 0.6:

With warning.alpha = 1.0:

Using 0.6 and 1.0 looks like the same, so I assume it is an issue related to blending colors (might be wrong though). Also note that the color works completely fine before exceeding colorcolumn. It just disappears after exceeding with an alpha value lower than 0.5.

I also tested with this minimal.lua, where I only added the plugin and run :set cc=80 after opening the file, and the issue is still there.

-- Run this file as `nvim --clean -u minimal.lua`

for name, url in pairs {
  -- ADD PLUGINS _NECESSARY_ TO REPRODUCE THE ISSUE, e.g:
  -- 'https://github.com/author1/plugin1',
  -- 'https://github.com/author2/plugin2',
  'https://github.com/Bekaboo/deadcolumn.nvim',
} do
  local install_path = vim.fn.fnamemodify('nvim_issue/' .. name, ':p')
  if vim.fn.isdirectory(install_path) == 0 then
    vim.fn.system { 'git', 'clone', '--depth=1', url, install_path }
  end
  vim.opt.runtimepath:append(install_path)
end

-- ADD INIT.LUA SETTINGS _NECESSARY_ FOR REPRODUCING THE ISSUE

[Bekaboo]

Cannot reproduce, this is what I get using {warning={alpha=0.6}} and {warning={alpha=1}}j: