Use `set t_Co=256` to enable support for `xterm-256color`. Then `highlight CursorLine ctermbg=235` makes
the cursorline slightly off-black to make it easier to see where you are. Sometimes underlining the cursor line
helps, but this makes it impossible to distinguish underscores from whitespace.
```vim
set t_Co=256
highlight CursorLine ctermbg=235
```
## From my .vimrc
```vim
colorscheme default
highlight LineNr ctermfg=yellow ctermbg=darkblue
highlight CursorLineNr ctermfg=black ctermbg=blue
function CLNoUnderline()
  highlight CursorLine cterm=none
endfunction
function CLUnderline()
  highlight CursorLine cterm=underline
endfunction
" highlight CursorLine ctermbg=darkgray
set t_Co=256
highlight CursorLine ctermbg=235
call CLNoUnderline()
```