Related: #192, #210, #248
Also #247 is about `NonText`, which needs investigating.
Issues: `:digraphs`, special keys in `:map` output, and certain parts of
`'listchars'` are "subtle" and hard to read (esp. w/ `cursorline` over
them). Also, vim uses `SpecialKey` for them (instead of `Whitespace` for
`'listchars'` and `SpecialKey` elsewhere, like NeoVim).
Fix: make `SpecialKey` more like special keys (the highlight in vimscript
for, e.g., `map <Space> :echo "hello"<CR>`). This has the side effect of
making digraphs more visible. It also makes certain `'listchars'` pink,
which may be annoying. But there is no way currently to separate the two
in vim.
Rationale: It matches with the special keys in maps. The fact that vim
uses it elsewhere may simply be "wrong" and need changed.
If you don't like it: well, as usual, you can use an autocommand to use
whatever colors you want (`:help dracula-customization`).
869f70a760