fix(colorscheme): distinguish CursorLine/Folded/StatusLineNC highlights #32256

Problem: currently `CursorLine`, `Folded`, `StatusLineNC` highlight
  groups have the same background color in default color scheme (Grey3).
  This is a result of optimizing their highlighting to be different from
  `Normal` but not draw too much attention.

  However, this design has a usability issue as those groups are
  sometimes appear together which can make it hard (but not impossible)
  to differentiate between them.

  This was previously partially resolved with `StatusLineNC` using Grey1
  as background (and thus be different from `CursorLine` but closer to
  `Normal`), but optimizing more towards it being a visible separator
  between windows was decided to be more important.

Solution: make `Folded` use Grey1 and `StatusLineNC` use Grey4. This
  makes all three highlight groups have different backgrounds with the
  following consequences:
    - Folds now have the same background as floating windows. It makes
      them there differentiable only by the value of 'foldtext' (which
      is usually enough). Optimizing for the case "cursor line is next
      to the fold" seems to be more useful than for the case "make folds
      in floating window differ by background".
    - Statusline of inactive windows now draw more attention to them.
      The benefits are that they are different from cursor column and
      are better window separators.
    - Inactive tabline (both `TabLine` and `TabLineFill`) now also draws
      a bit more attention to it (as they are linked to `StatusLineNC`)
      but with the benefit of also being different from `CursorLine`.

0 files changed, 0 insertions, 0 deletions