[HELP]: Cannot set the icon background.

### Is there an existing issue for this?

- [x] I have searched the existing issues

### What happened?

I cannot get the icon background to a desired color.

I am using Plug to install the plugin.

This is the result of my config:

### What did you expect to happen?

The icon background allowed to be changed.

### Config

```lua
Below is my bufferline config:

```lua
local bufferline_ok, bufferline = pcall(require, 'bufferline');

if not bufferline_ok then
return;
end

vim.opt.termguicolors = true;

bufferline.setup({
options = {
themable = true,
move_wraps_at_ends = true
},
highlights = {
info_selected = {
bg = '#282828',
fg = '#282828'
},
separator_selected = {
bg = '#282828',
fg = '#282828'
},
tab_separator_selected = {
bg = '#282828',
fg = '#282828',
sp = '#282828'
},
buffer_selected = {
bg = '#eeeeee',
fg = '#282828'
},
tab_selected = {
bg = '#282828',
fg = '#282828'
},
}
});
```

### Additional Information

Plug install will output the following tag:
`Latest tag for * -> v4.9.1 (bufferline.nvim)`

### commit

_No response_