[theme] Fix color problem of steeef theme

steeef theme sets colors depending on $TERM, however if %F is
used, it must be closed by %f instead of %{$reset_color%}.

Further on, all %f directives have been replaced by %F and color
support of current TERM is checked more properly.

themes/steeef.zsh-theme

@@ -10,7 +10,7 @@
 export VIRTUAL_ENV_DISABLE_PROMPT=1
 
 function virtualenv_info {
-    [ $VIRTUAL_ENV ] && echo '('$fg[blue]`basename $VIRTUAL_ENV`%{$reset_color%}') '
+    [ $VIRTUAL_ENV ] && echo '('%F{blue}`basename $VIRTUAL_ENV`%f') '
 }
 PR_GIT_UPDATE=1
 
@@ -20,18 +20,18 @@ autoload -U add-zsh-hook
 autoload -Uz vcs_info
 
 #use extended color pallete if available
-if [[ $TERM = *256color* || $TERM = *rxvt* ]]; then
+if [[ $terminfo[colors] -ge 256 ]]; then
     turquoise="%F{81}"
     orange="%F{166}"
     purple="%F{135}"
     hotpink="%F{161}"
     limegreen="%F{118}"
 else
-    turquoise="$fg[cyan]"
-    orange="$fg[yellow]"
-    purple="$fg[magenta]"
-    hotpink="$fg[red]"
-    limegreen="$fg[green]"
+    turquoise="%F{cyan}"
+    orange="%F{yellow}"
+    purple="%F{magenta}"
+    hotpink="%F{red}"
+    limegreen="%F{green}"
 fi
 
 # enable VCS systems you use
@@ -48,7 +48,7 @@ zstyle ':vcs_info:*:prompt:*' check-for-changes true
 # %a - action (e.g. rebase-i)
 # %R - repository path
 # %S - path in the repository
-PR_RST="%{${reset_color}%}"
+PR_RST="%f"
 FMT_BRANCH="(%{$turquoise%}%b%u%c${PR_RST})"
 FMT_ACTION="(%{$limegreen%}%a${PR_RST})"
 FMT_UNSTAGED="%{$orange%}●"
@@ -96,5 +96,5 @@ function steeef_precmd {
 add-zsh-hook precmd steeef_precmd
 
 PROMPT=$'
-%{$purple%}%n%{$reset_color%} at %{$orange%}%m%{$reset_color%} in %{$limegreen%}%~%{$reset_color%} $vcs_info_msg_0_$(virtualenv_info)%{$reset_color%}
+%{$purple%}%n${PR_RST} at %{$orange%}%m${PR_RST} in %{$limegreen%}%~${PR_RST} $vcs_info_msg_0_$(virtualenv_info)
 $ '