Remove a ton of `set_color normal` calls.

Eases the pain of fish-shell/fish-shell#3793 just a bit.

This _shouldn't_ ever look any different to the end user. I think.

fish_prompt.fish

@@ -224,8 +224,7 @@ function __bobthefish_start_segment -S -d 'Start a prompt segment'
   set -e argv[1]
 
   set_color normal # clear out anything bold or underline...
-  set_color -b $bg
-  set_color $fg $argv
+  set_color -b $bg $fg $argv
 
   switch "$__bobthefish_current_bg"
     case ''
@@ -271,7 +270,6 @@ function __bobthefish_path_segment -S -a current_dir -d 'Display a shortened for
   echo -n $parent
   set_color -b $segment_basename_color
   echo -ns $directory ' '
-  set_color normal
 end
 
 function __bobthefish_finish_segments -S -d 'Close open prompt segments'
@@ -281,8 +279,8 @@ function __bobthefish_finish_segments -S -d 'Close open prompt segments'
     echo -ns $__bobthefish_right_black_arrow_glyph ' '
   end
 
-  set __bobthefish_current_bg
   set_color normal
+  set __bobthefish_current_bg
 end
 
 
@@ -331,7 +329,6 @@ function __bobthefish_prompt_vagrant_vbox -S -a id -d 'Display VirtualBox Vagran
 
   __bobthefish_start_segment $__color_vagrant
   echo -ns $vagrant_status ' '
-  set_color normal
 end
 
 function __bobthefish_prompt_vagrant_vmware -S -a id -d 'Display VMWare Vagrant status'
@@ -345,7 +342,6 @@ function __bobthefish_prompt_vagrant_vmware -S -a id -d 'Display VMWare Vagrant
 
   __bobthefish_start_segment $__color_vagrant
   echo -ns $vagrant_status ' '
-  set_color normal
 end
 
 function __bobthefish_prompt_vagrant_parallels -S -d 'Display Parallels Vagrant status'
@@ -369,14 +365,12 @@ function __bobthefish_prompt_vagrant_parallels -S -d 'Display Parallels Vagrant
 
   __bobthefish_start_segment $__color_vagrant
   echo -ns $vagrant_status ' '
-  set_color normal
 end
 
 function __bobthefish_prompt_docker -S -d 'Show docker machine name'
     [ "$theme_display_docker_machine" = 'no' -o -z "$DOCKER_MACHINE_NAME" ]; and return
     __bobthefish_start_segment $__color_vagrant
     echo -ns $DOCKER_MACHINE_NAME ' '
-    set_color normal
 end
 
 function __bobthefish_prompt_status -S -a last_status -d 'Display symbols for a non zero exit status, root and background jobs'
@@ -399,7 +393,8 @@ function __bobthefish_prompt_status -S -a last_status -d 'Display symbols for a
   if [ "$nonzero" -o "$superuser" -o "$bg_jobs" ]
     __bobthefish_start_segment $__color_initial_segment_exit
     if [ "$nonzero" ]
-       set_color normal; set_color -b $__color_initial_segment_exit
+      set_color normal
+      set_color -b $__color_initial_segment_exit
       if [ "$theme_show_exit_status" = 'yes' ]
       	echo -ns $last_status ' '
       else
@@ -408,16 +403,16 @@ function __bobthefish_prompt_status -S -a last_status -d 'Display symbols for a
     end
 
     if [ "$superuser" ]
-      set_color normal; set_color -b $__color_initial_segment_su
+      set_color normal
+      set_color -b $__color_initial_segment_su
       echo -n $__bobthefish_superuser_glyph
     end
 
     if [ "$bg_jobs" ]
-      set_color normal; set_color -b $__color_initial_segment_jobs
+      set_color normal
+      set_color -b $__color_initial_segment_jobs
       echo -n $__bobthefish_bg_job_glyph
     end
-
-    set_color normal
   end
 end
 
@@ -543,9 +538,11 @@ function __bobthefish_prompt_git -S -a current_dir -d 'Display the actual git st
       if [ "$work_parent" ]
         echo -n "$work_parent/"
       end
-      set_color normal; set_color -b $__color_repo_work_tree
+      set_color normal
+      set_color -b $__color_repo_work_tree
       echo -n (basename $work_dir)
-      set_color normal; set_color --background $colors
+      set_color normal
+      set_color -b $colors
       [ "$project_pwd" ]
         and echo -n '/'
     end
@@ -590,7 +587,6 @@ function __bobthefish_prompt_vi -S -d 'Display vi mode'
       __bobthefish_start_segment $__color_vi_mode_visual
       echo -n 'V '
   end
-  set_color normal
 end
 
 function __bobthefish_virtualenv_python_version -S -d 'Get current python version'
@@ -614,7 +610,6 @@ function __bobthefish_prompt_virtualfish -S -d "Display activated virtual enviro
     echo -ns $__bobthefish_virtualenv_glyph $version_glyph ' '
   end
   echo -ns (basename "$VIRTUAL_ENV") ' '
-  set_color normal
 end
 
 function __bobthefish_rvm_parse_ruby -S -a ruby_string scope -d 'Parse RVM Ruby string'
@@ -689,7 +684,6 @@ function __bobthefish_show_ruby -S -d 'Current Ruby (rvm/rbenv)'
   [ -z "$ruby_version" ]; and return
   __bobthefish_start_segment $__color_rvm
   echo -ns $__bobthefish_ruby_glyph $ruby_version ' '
-  set_color normal
 end
 
 function __bobthefish_prompt_rubies -S -d 'Display current Ruby information'