Add script to change an xterm color palette.

Readme.md

@@ -15,14 +15,18 @@ differently (for instance, I have tried to avoid red on blue).
 
 The main reason for the existence of this project is that the original Solarized
 theme does not define `guifg` and `guibg` in terminal Vim, making it unsuitable
-for versions of Vim supporting true-color terminals. Instead, this color scheme
+for versions of Vim supporting true-color (i.e., 24-bit color) terminals.
-works **out of the box everywhere**. For the best experience, you need:
+Instead, this colorscheme works **out of the box everywhere**. For the best
+experience, you need:
 
 - Vim ≥7.4.1799, or NeoVim, with `termguicolors` set, **and**
 - [a true-color enabled terminal](https://gist.github.com/XVilka/8346728).
 
 Solarized 8 also works in MacVim, gVim, etc…: no configuration is needed.
 
+
+## But, my terminal has only 256 colors!
+
 For terminals not supporting true colors, Solarized 8 will fall back
 to use an approximate palette based on xterm's 256 colors. This is a very crude
 approximation, which looks more or less like this:
@@ -34,17 +38,28 @@ Dark 256 color palette     |  Light 256 color palette
 (Yeah, it looks like a different colorscheme.)
 
 If you don't like this approximation, to get exact colors with such terminals
-you must set your terminal's 16 ANSI colors to the Solarized palette (refer to
+you have two possibilities:
-the manual of your terminal) and put this line in your `vimrc` before loading
+
-the colorscheme:
+1. Modify some of your terminal colors in the range 16–255 to match Solarized
+   palette. For this purpose, you may run `scripts/solarized8.sh`; no setting is
+   needed in Vim. Note, however, that this is not supported by all terminals
+   (e.g., in macOS's Terminal.app this approach does not work: the script has no
+   effect).
+
+2. Set your terminal's 16 ANSI colors (the colors in the range 0–15) to the
+   Solarized palette. Most terminals allow you to do that: see the manual of
+   your terminal to learn how. Then, put this line in your `vimrc` before
+   loading the colorscheme:
 
    ```vim
    let g:solarized_use16 = 1
    ```
 
-Be aware that, if you set the variable above, but your terminal does not use the
+   Be aware that, if you set the variable above, but your terminal does not use
-Solarized palette, your colors will be completely off. Note also that if your
+   the Solarized palette, your colors will be completely off.
-terminal does not support true colors, you must *not* set `termguicolors`.
+
+Finally, if your terminal does not support true colors, you must *not* set
+`termguicolors`.
 
 
 ## Installation
@@ -135,8 +150,8 @@ See `:h xterm-true-color` for the details.
 
 Do you want to hack the theme? Install
 [Colortemplate](https://github.com/lifepillar/vim-colortemplate), edit the
-`*.colortemplate` files, then rebuild the colorschemes by sourcing the script in
+`*.colortemplate` files, then rebuild the colorschemes by sourcing
-the `templates` folder.
+`scripts/make_colorschemes.vim`.
 
 If you extend or improve Solarized 8, please consider submitting a pull request!
 

scripts/make_colorschemes.vim

@@ -5,11 +5,12 @@
 
 let s:curdir = fnamemodify(resolve(expand('<sfile>:p')), ':h')
 let s:parent = fnamemodify(s:curdir, ':h')
+let s:templates = s:parent.'/templates'
 let s:errors = 0
 
-execute 'lcd' s:curdir
+execute 'lcd' s:templates
 
-for s:template in glob(s:curdir . '/solarized8*.colortemplate', 1, 1)
+for s:template in glob(s:templates . '/solarized8*.colortemplate', 1, 1)
   let s:template_name = fnamemodify(s:template, ':t:r')
   if s:template_name == 'solarized8'
     let g:colortemplate_no_doc = 0

scripts/solarized8.sh

@@ -0,0 +1,72 @@
+#!/bin/sh
+# Modify 256-color palette in supported terminals
+# Script adapted from https://github.com/chriskempson/base16-shell
+set -o errexit
+
+hex2rgb() {
+  local s=$1
+  local r=${s:1:2}
+  local g=${s:3:2}
+  local b=${s:5:2}
+  echo "$r/$g/$b"
+}
+
+if [ "${TERM%%-*}" = 'linux' ]; then
+  # This script doesn't support linux console
+  return 2>/dev/null || exit 0
+fi
+
+if [ -n "$TMUX" ]; then
+  # tell tmux to pass the escape sequences through
+  # (Source: http://permalink.gmane.org/gmane.comp.terminal-emulators.tmux.user/1324)
+  printf_template="\033Ptmux;\033\033]4;%d;rgb:%s\007\033\\"
+  printf_template_var="\033Ptmux;\033\033]%d;rgb:%s\007\033\\"
+  printf_template_custom="\033Ptmux;\033\033]%s%s\007\033\\"
+elif [ "${TERM%%-*}" = "screen" ]; then
+  # GNU screen (screen, screen-256color, screen-256color-bce)
+  printf_template="\033P\033]4;%d;rgb:%s\007\033\\"
+  printf_template_var="\033P\033]%d;rgb:%s\007\033\\"
+  printf_template_custom="\033P\033]%s%s\007\033\\"
+else
+  printf_template="\033]4;%d;rgb:%s\033\\"
+  printf_template_var="\033]%d;rgb:%s\033\\"
+  printf_template_custom="\033]%s%s\033\\"
+fi
+
+printf $printf_template 235 $(hex2rgb "#002b36")
+printf $printf_template 236 $(hex2rgb "#073642")
+printf $printf_template 242 $(hex2rgb "#586e75")
+printf $printf_template 66 $(hex2rgb "#657b83")
+printf $printf_template 246 $(hex2rgb "#839496")
+printf $printf_template 247 $(hex2rgb "#93a1a1")
+printf $printf_template 254 $(hex2rgb "#eee8d5")
+printf $printf_template 230 $(hex2rgb "#fdf6e3")
+printf $printf_template 136 $(hex2rgb "#b58900")
+printf $printf_template 166 $(hex2rgb "#cb4b16")
+printf $printf_template 160 $(hex2rgb "#dc322f")
+printf $printf_template 162 $(hex2rgb "#d33682")
+printf $printf_template 61 $(hex2rgb "#6c71c4")
+printf $printf_template 32 $(hex2rgb "#268bd2")
+printf $printf_template 37 $(hex2rgb "#2aa198")
+printf $printf_template 106 $(hex2rgb "#859900")
+
+# foreground / background / cursor color
+# if [ -n "$ITERM_SESSION_ID" ]; then
+#   # iTerm2 proprietary escape codes
+#   printf $printf_template_custom Pg 93a1a1 # forground
+#   printf $printf_template_custom Ph 002b36 # background
+#   printf $printf_template_custom Pi 93a1a1 # bold color
+#   printf $printf_template_custom Pj 586e75 # selection color
+#   printf $printf_template_custom Pk 93a1a1 # selected text color
+#   printf $printf_template_custom Pl 93a1a1 # cursor
+#   printf $printf_template_custom Pm 002b36 # cursor text
+# else
+#   printf $printf_template_var 10 $color_foreground
+#   printf $printf_template_var 11 $color_background
+#   printf $printf_template_var 12 $color_cursor
+# fi
+
+unset printf_template
+unset printf_template_var
+unset printf_template_custom
+

templates/_fix-256-palette.colortemplate

@@ -0,0 +1,74 @@
+auxfile scripts/@shortname.sh
+#!/bin/sh
+# Modify 256-color palette in supported terminals
+# Script adapted from https://github.com/chriskempson/base16-shell
+set -o errexit
+
+hex2rgb() {
+  local s=$1
+  local r=${s:1:2}
+  local g=${s:3:2}
+  local b=${s:5:2}
+  echo "$r/$g/$b"
+}
+
+if [ "${TERM%%-*}" = 'linux' ]; then
+  # This script doesn't support linux console
+  return 2>/dev/null || exit 0
+fi
+
+if [ -n "$TMUX" ]; then
+  # tell tmux to pass the escape sequences through
+  # (Source: http://permalink.gmane.org/gmane.comp.terminal-emulators.tmux.user/1324)
+  printf_template="\033Ptmux;\033\033]4;%d;rgb:%s\007\033\\"
+  printf_template_var="\033Ptmux;\033\033]%d;rgb:%s\007\033\\"
+  printf_template_custom="\033Ptmux;\033\033]%s%s\007\033\\"
+elif [ "${TERM%%-*}" = "screen" ]; then
+  # GNU screen (screen, screen-256color, screen-256color-bce)
+  printf_template="\033P\033]4;%d;rgb:%s\007\033\\"
+  printf_template_var="\033P\033]%d;rgb:%s\007\033\\"
+  printf_template_custom="\033P\033]%s%s\007\033\\"
+else
+  printf_template="\033]4;%d;rgb:%s\033\\"
+  printf_template_var="\033]%d;rgb:%s\033\\"
+  printf_template_custom="\033]%s%s\033\\"
+fi
+
+printf $printf_template @term256base03 $(hex2rgb "@guibase03")
+printf $printf_template @term256base02 $(hex2rgb "@guibase02")
+printf $printf_template @term256base01 $(hex2rgb "@guibase01")
+printf $printf_template @term256base00 $(hex2rgb "@guibase00")
+printf $printf_template @term256base0 $(hex2rgb "@guibase0")
+printf $printf_template @term256base1 $(hex2rgb "@guibase1")
+printf $printf_template @term256base2 $(hex2rgb "@guibase2")
+printf $printf_template @term256base3 $(hex2rgb "@guibase3")
+printf $printf_template @term256yellow $(hex2rgb "@guiyellow")
+printf $printf_template @term256orange $(hex2rgb "@guiorange")
+printf $printf_template @term256red $(hex2rgb "@guired")
+printf $printf_template @term256magenta $(hex2rgb "@guimagenta")
+printf $printf_template @term256violet $(hex2rgb "@guiviolet")
+printf $printf_template @term256blue $(hex2rgb "@guiblue")
+printf $printf_template @term256cyan $(hex2rgb "@guicyan")
+printf $printf_template @term256green $(hex2rgb "@guigreen")
+
+# foreground / background / cursor color
+# if [ -n "$ITERM_SESSION_ID" ]; then
+#   # iTerm2 proprietary escape codes
+#   printf $printf_template_custom Pg 93a1a1 # forground
+#   printf $printf_template_custom Ph 002b36 # background
+#   printf $printf_template_custom Pi 93a1a1 # bold color
+#   printf $printf_template_custom Pj 586e75 # selection color
+#   printf $printf_template_custom Pk 93a1a1 # selected text color
+#   printf $printf_template_custom Pl 93a1a1 # cursor
+#   printf $printf_template_custom Pm 002b36 # cursor text
+# else
+#   printf $printf_template_var 10 $color_foreground
+#   printf $printf_template_var 11 $color_background
+#   printf $printf_template_var 12 $color_cursor
+# fi
+
+unset printf_template
+unset printf_template_var
+unset printf_template_custom
+endauxfile
+

templates/solarized8.colortemplate

@@ -40,6 +40,10 @@ Color: green                #859900                ~        2
 Color: back                 #002b36                ~        8
 # }}}
 
+# Fix 256-color palette in supported terminals {{{
+Include: _fix-256-palette.colortemplate
+# }}}
+
 # Default highlight groups {{{
 verbatim
 if !has('gui_running') && get(g:, '@optionprefix_termtrans', 0)