my-nvim-setup/lua/bufferline/lua.lua

vim.o.termguicolors = true 

require'bufferline'.setup{
  options = {
    buffer_close_icon= '',
    modified_icon = '●',
    close_icon = '',
    left_trunc_marker = '',
    right_trunc_marker = '',
    max_name_length = 14,
    max_prefix_length = 13, 
    tab_size = 18,
    enforce_regular_tabs = true ,
   view = "multiwindow" ,
    show_buffer_close_icons = true ,
    separator_style = "thin" 
    },

      highlights = {
        background = {
        guifg = comment_fg,
        guibg = '#282c34'
     },
      fill = {
        guifg = comment_fg,
        guibg = '#282c34' 
      },
        buffer_selected = {
        guifg = normal_fg,
        guibg =  '#3A3E44',
        gui = "bold"
      }, 
       separator_visible = {
        guifg = '#282c34' ,
        guibg = '#282c34'
        },
        separator_selected = {
        guifg = '#282c34'  ,
        guibg = '#282c34'
      },
      separator = {
        guifg = '#282c34' ,
        guibg = '#282c34' 
      },
      indicator_selected = {
         guifg = '#282c34' ,
        guibg = '#282c34'  
      },
        modified_selected = {
        guifg = string_fg,
        guibg = '#3A3E44'
      }
   };  
}