feat(ys): increase color contrast with light color schemes (#10295)

themes/ys.zsh-theme

@@ -5,8 +5,10 @@
 #
 # Mar 2013 Yad Smood
 
+typeset +H my_gray="$FG[247]"
+
 # VCS
-YS_VCS_PROMPT_PREFIX1=" %{$fg[white]%}on%{$reset_color%} "
+YS_VCS_PROMPT_PREFIX1=" %{$my_gray%}on%{$reset_color%} "
 YS_VCS_PROMPT_PREFIX2=":%{$fg[cyan]%}"
 YS_VCS_PROMPT_SUFFIX="%{$reset_color%}"
 YS_VCS_PROMPT_DIRTY=" %{$fg[red]%}x"
@@ -60,13 +62,13 @@ local exit_code="%(?,,C:%{$fg[red]%}%?%{$reset_color%})"
 PROMPT="
 %{$terminfo[bold]$fg[blue]%}#%{$reset_color%} \
 %(#,%{$bg[yellow]%}%{$fg[black]%}%n%{$reset_color%},%{$fg[cyan]%}%n) \
-%{$fg[white]%}@ \
+%{$my_gray%}@ \
 %{$fg[green]%}%m \
-%{$fg[white]%}in \
+%{$my_gray%}in \
 %{$terminfo[bold]$fg[yellow]%}%~%{$reset_color%}\
 ${hg_info}\
 ${git_info}\
 ${venv_info}\
  \
-%{$fg[white]%}[%*] $exit_code
+%{$my_gray%}[%*] $exit_code
 %{$terminfo[bold]$fg[red]%}$ %{$reset_color%}"