diff --git a/README.md b/README.md
index a46505d..3174c67 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,8 @@ so you can omit it if you use a plugin manager that doesn't support hooks.
 
 - [fzf][fzf-main] 0.23.0 or above
 - For syntax-highlighted preview, install [bat](https://github.com/sharkdp/bat)
-- `:GF?` will use [delta](https://github.com/dandavison/delta) if available
+- If [delta](https://github.com/dandavison/delta) is available, `:GF?`,
+  `:Commits` and `:BCommits` will use it to format `git diff` output.
   to format `git diff` output
 - `Ag` requires [The Silver Searcher (ag)][ag]
 - `Rg` requires [ripgrep (rg)][rg]
diff --git a/autoload/fzf/vim.vim b/autoload/fzf/vim.vim
index b259835..b56a2a6 100644
--- a/autoload/fzf/vim.vim
+++ b/autoload/fzf/vim.vim
@@ -1221,8 +1221,9 @@ function! s:commits(buffer_local, args)
   endif
 
   if !s:is_win && &columns > s:wide
+    let suffix = executable('delta') ? '| delta' : '--color=always'
     call extend(options.options,
-    \ ['--preview', 'echo {} | grep -o "[a-f0-9]\{7,\}" | head -1 | xargs git show --format=format: --color=always | head -1000'])
+    \ ['--preview', 'echo {} | grep -o "[a-f0-9]\{7,\}" | head -1 | xargs git show --format=format: ' . suffix])
   endif
 
   return s:fzf(a:buffer_local ? 'bcommits' : 'commits', options, a:args)
diff --git a/doc/fzf-vim.txt b/doc/fzf-vim.txt
index ab1ec5f..2641683 100644
--- a/doc/fzf-vim.txt
+++ b/doc/fzf-vim.txt
@@ -1,4 +1,4 @@
-fzf-vim.txt	fzf-vim	Last change: December 12 2020
+fzf-vim.txt	fzf-vim	Last change: December 14 2020
 FZF-VIM - TABLE OF CONTENTS                                *fzf-vim* *fzf-vim-toc*
 ==============================================================================
 
@@ -92,7 +92,8 @@ so you can omit it if you use a plugin manager that doesn't support hooks.
 
  - {fzf}{1} 0.23.0 or above
  - For syntax-highlighted preview, install {bat}{5}
- - `:GF?` will use {delta}{6} if available to format `git diff` output
+ - If {delta}{6} is available, `:GF?`, `:Commits` and `:BCommits` will use it to
+   format `git diff` output. to format `git diff` output
  - `Ag` requires {The Silver Searcher (ag)}{7}
  - `Rg` requires {ripgrep (rg)}{8}
  - `Tags` and `Helptags` require Perl