Coloring and spaces of the ":Buffers" command

### Checklist

- [X] I have fzf 0.54.0 or later
- [X] I have searched through the existing issues

### Output of `:echo system(fzf#exec() .. ' --version')`

0.57.0 (0476a65)

### OS

- [X] Linux
- [ ] macOS
- [ ] Windows
- [ ] Etc.

### Problem / Steps to reproduce

Just wanted to ask about the coloring (and the 2 spaces) of the `:Buffers` command, specifically how it applies them to the current buffer on top. I've modified `fzf#vim#_format_buffer(b)` in the `fzf.vim/autoload/fzf/vim.vim` to my liking, but I can't find this cyan coloring and spacing anywhere. I tried changing all of the `let s:ansi` to the same number, but it had no effect.

Start in fzf.vim/autoload/fzf/vim.vim, including fzf#vim#_format_buffer(b), and trace how the :Buffers output applies coloring and spacing to the current buffer. Compare the formatting path with the displayed result and document or correct the behavior so the intended coloring and spacing are clear.

Written by the indexing model from the issue text.