diff --git a/highlighters/main/test-data/alias-assignment1.zsh b/highlighters/main/test-data/alias-assignment1.zsh
index 3cdf4e6..cf5be75 100644
--- a/highlighters/main/test-data/alias-assignment1.zsh
+++ b/highlighters/main/test-data/alias-assignment1.zsh
@@ -30,7 +30,6 @@
 # Issue #263 (more-pathological case): aliases[x=y]=z works; the ${(z)} splitter considers
 # that a single word; but it's not looked up as an alias.  Hence, highlight it as an error.
 aliases[x=y]='lorem ipsum dolor sit amet'
-ZSH_HIGHLIGHT_STYLES[alias]=$unused_highlight
 BUFFER='x=y ls'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/alias.zsh b/highlighters/main/test-data/alias.zsh
index 344f0de..5129614 100644
--- a/highlighters/main/test-data/alias.zsh
+++ b/highlighters/main/test-data/alias.zsh
@@ -31,7 +31,6 @@ alias alias1="unused expansion"
 alias -s alias2="echo"
 alias1() {} # to check that it's highlighted as an alias, not as a function
 
-ZSH_HIGHLIGHT_STYLES[alias]=$unused_highlight
 BUFFER='x.alias2; alias1'
 
 # Set expected_region_highlight as a function of zsh version.
diff --git a/highlighters/main/test-data/assign-append.zsh b/highlighters/main/test-data/assign-append.zsh
index 82b48f9..6485f0e 100644
--- a/highlighters/main/test-data/assign-append.zsh
+++ b/highlighters/main/test-data/assign-append.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[assign]=$unused_highlight
 BUFFER='a+=(lorem ipsum)'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/assign-array.zsh b/highlighters/main/test-data/assign-array.zsh
index be3f13b..8995162 100644
--- a/highlighters/main/test-data/assign-array.zsh
+++ b/highlighters/main/test-data/assign-array.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[assign]=$unused_highlight
 BUFFER='(A=(hello world))'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/assign-semicolon.zsh b/highlighters/main/test-data/assign-semicolon.zsh
index 8fe2964..c2618b0 100644
--- a/highlighters/main/test-data/assign-semicolon.zsh
+++ b/highlighters/main/test-data/assign-semicolon.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[commandseparator]=$unused_highlight
 BUFFER='A=1; echo hello world'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/assign-subshell.zsh b/highlighters/main/test-data/assign-subshell.zsh
index f9639fe..77cdd65 100644
--- a/highlighters/main/test-data/assign-subshell.zsh
+++ b/highlighters/main/test-data/assign-subshell.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[assign]=$unused_highlight
 BUFFER='(A=1)'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/assign.zsh b/highlighters/main/test-data/assign.zsh
index 9148d52..7e18731 100644
--- a/highlighters/main/test-data/assign.zsh
+++ b/highlighters/main/test-data/assign.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[assign]=$unused_highlight
 BUFFER='A=1 b=("foo" bar)'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/back-quoted-argument.zsh b/highlighters/main/test-data/back-quoted-argument.zsh
index cd73212..f8329ea 100644
--- a/highlighters/main/test-data/back-quoted-argument.zsh
+++ b/highlighters/main/test-data/back-quoted-argument.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[back-quoted-argument]=$unused_highlight
 BUFFER='echo `echo 42`'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/commandseparator.zsh b/highlighters/main/test-data/commandseparator.zsh
index e478318..e8d93a6 100644
--- a/highlighters/main/test-data/commandseparator.zsh
+++ b/highlighters/main/test-data/commandseparator.zsh
@@ -27,8 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[commandseparator]=$unused_highlight
-
 BUFFER=':; pwd &! ls'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/control-flow.zsh b/highlighters/main/test-data/control-flow.zsh
index 58a696b..2f6a160 100644
--- a/highlighters/main/test-data/control-flow.zsh
+++ b/highlighters/main/test-data/control-flow.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[alias]=$unused_highlight
 BUFFER='while if echo Hello; then ls /; else ls; fi; do stat "x"; done; repeat 10 ls'
 
 expected_region_highlight+=(
diff --git a/highlighters/main/test-data/dollar-quoted.zsh b/highlighters/main/test-data/dollar-quoted.zsh
index cfeb6d3..8c4c16f 100644
--- a/highlighters/main/test-data/dollar-quoted.zsh
+++ b/highlighters/main/test-data/dollar-quoted.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[dollar-quoted-argument]=$unused_highlight
 BUFFER=": \$'*' 'foo'"
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/dollar-quoted2.zsh b/highlighters/main/test-data/dollar-quoted2.zsh
index 03afc66..a69373f 100644
--- a/highlighters/main/test-data/dollar-quoted2.zsh
+++ b/highlighters/main/test-data/dollar-quoted2.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[back-dollar-quoted-argument]=$unused_highlight
 BUFFER=": \$'foo\xbar\udeadbeef\uzzzz'"
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/dollar-quoted3.zsh b/highlighters/main/test-data/dollar-quoted3.zsh
index cb5bd77..320cd94 100644
--- a/highlighters/main/test-data/dollar-quoted3.zsh
+++ b/highlighters/main/test-data/dollar-quoted3.zsh
@@ -28,7 +28,6 @@
 # -------------------------------------------------------------------------------------------------
 
 # Similar to double-quoted2.zsh
-ZSH_HIGHLIGHT_STYLES[back-dollar-quoted-argument]=$unused_highlight
 # This test checks that the '1' gets highlighted correctly.  Do not append to the BUFFER.
 BUFFER=": \$'\xa1"
 
diff --git a/highlighters/main/test-data/double-hyphen-option.zsh b/highlighters/main/test-data/double-hyphen-option.zsh
index 3339d89..9728cd8 100644
--- a/highlighters/main/test-data/double-hyphen-option.zsh
+++ b/highlighters/main/test-data/double-hyphen-option.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[double-hyphen-option]=$unused_highlight
 BUFFER='hello --world'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/exec-redirection1.zsh b/highlighters/main/test-data/exec-redirection1.zsh
index 47fd9f6..784ec47 100644
--- a/highlighters/main/test-data/exec-redirection1.zsh
+++ b/highlighters/main/test-data/exec-redirection1.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[redirection]=$unused_highlight
 BUFFER='exec {foo}>&/tmp ls'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/function.zsh b/highlighters/main/test-data/function.zsh
index 27c60a1..6876391 100644
--- a/highlighters/main/test-data/function.zsh
+++ b/highlighters/main/test-data/function.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[function]=$unused_highlight
 cd() {
   builtin cd "$@"
 }
@@ -36,8 +35,6 @@ ls() {
 }
 BUFFER='cd;ls'
 
-# Use $unused_highlight to see that function highlighting has precedence over command and builtin
-
 expected_region_highlight=(
   "1 2 function" # cd
   "4 5 function" # ls
diff --git a/highlighters/main/test-data/hashed-command.zsh b/highlighters/main/test-data/hashed-command.zsh
index 1cc24b0..83b0ed6 100644
--- a/highlighters/main/test-data/hashed-command.zsh
+++ b/highlighters/main/test-data/hashed-command.zsh
@@ -28,7 +28,6 @@
 # -------------------------------------------------------------------------------------------------
 
 hash zsh_syntax_highlighting_hash=/doesnotexist
-ZSH_HIGHLIGHT_STYLES[hashed-command]=$unused_highlight
 BUFFER='zsh_syntax_highlighting_hash'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/history-expansion.zsh b/highlighters/main/test-data/history-expansion.zsh
index be511b0..3e23711 100644
--- a/highlighters/main/test-data/history-expansion.zsh
+++ b/highlighters/main/test-data/history-expansion.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[default]=$unused_highlight
 BUFFER='!foo bar !baz ! ; !'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/multiline-string2.zsh b/highlighters/main/test-data/multiline-string2.zsh
index 3d45002..8ecce5b 100644
--- a/highlighters/main/test-data/multiline-string2.zsh
+++ b/highlighters/main/test-data/multiline-string2.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[double-quoted-argument]=$unused_highlight
 BUFFER=$'echo "foo1\n'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/path_prefix.zsh b/highlighters/main/test-data/path_prefix.zsh
index e945fe2..12fb30b 100644
--- a/highlighters/main/test-data/path_prefix.zsh
+++ b/highlighters/main/test-data/path_prefix.zsh
@@ -30,7 +30,6 @@
 # Assumes that '/bin/sh' exists and '/bin/s' does not exist.
 # Related to path_prefix2.zsh
 
-ZSH_HIGHLIGHT_STYLES[path_prefix]=$unused_highlight
 BUFFER='ls /bin/s'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/path_prefix2.zsh b/highlighters/main/test-data/path_prefix2.zsh
index 761c004..ffe50cd 100644
--- a/highlighters/main/test-data/path_prefix2.zsh
+++ b/highlighters/main/test-data/path_prefix2.zsh
@@ -30,7 +30,6 @@
 # Assumes that '/bin/sh' exists and '/bin/s' does not exist.
 # Related to path_prefix.zsh
 
-ZSH_HIGHLIGHT_STYLES[path_prefix]=$unused_highlight
 BUFFER='ls /bin/s'
 WIDGET=accept-line
 
diff --git a/highlighters/main/test-data/precommand.zsh b/highlighters/main/test-data/precommand.zsh
index 04697cf..a03b331 100644
--- a/highlighters/main/test-data/precommand.zsh
+++ b/highlighters/main/test-data/precommand.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[assign]=$unused_highlight
 BUFFER=': command zzzzzz'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/redirection.zsh b/highlighters/main/test-data/redirection.zsh
index e26fb7d..5086082 100644
--- a/highlighters/main/test-data/redirection.zsh
+++ b/highlighters/main/test-data/redirection.zsh
@@ -28,7 +28,6 @@
 # -------------------------------------------------------------------------------------------------
 
 # Redirection before and after the command word are implemented differently; test both.
-ZSH_HIGHLIGHT_STYLES[redirection]=$unused_highlight
 BUFFER='<<<foo echo >>&!bar'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/reserved-word.zsh b/highlighters/main/test-data/reserved-word.zsh
index 8442a4c..e71fe0a 100644
--- a/highlighters/main/test-data/reserved-word.zsh
+++ b/highlighters/main/test-data/reserved-word.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[reserved-word]=$unused_highlight
 BUFFER='repeat "1" do done'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/sudo-command.zsh b/highlighters/main/test-data/sudo-command.zsh
index 49fc6a6..4f8909e 100644
--- a/highlighters/main/test-data/sudo-command.zsh
+++ b/highlighters/main/test-data/sudo-command.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[single-hyphen-option]=$unused_highlight
 # Tests three codepaths:
 # * -i  (no argument)
 # * -C3 (pasted argument)
diff --git a/highlighters/main/test-data/sudo-comment.zsh b/highlighters/main/test-data/sudo-comment.zsh
index e66f13d..856567b 100644
--- a/highlighters/main/test-data/sudo-comment.zsh
+++ b/highlighters/main/test-data/sudo-comment.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[single-hyphen-option]=$unused_highlight
 setopt interactive_comments
 BUFFER='sudo -u # comment'
 
diff --git a/highlighters/main/test-data/sudo-redirection.zsh b/highlighters/main/test-data/sudo-redirection.zsh
index 5581c1b..f507899 100644
--- a/highlighters/main/test-data/sudo-redirection.zsh
+++ b/highlighters/main/test-data/sudo-redirection.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[redirection]=$unused_highlight
 BUFFER='sudo -u >/tmp otheruser ls; sudo ls; sudo -i ls'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/sudo-redirection2.zsh b/highlighters/main/test-data/sudo-redirection2.zsh
index 4a2d9d0..30f6ff8 100644
--- a/highlighters/main/test-data/sudo-redirection2.zsh
+++ b/highlighters/main/test-data/sudo-redirection2.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[redirection]=$unused_highlight
 BUFFER='sudo >/tmp -u otheruser ls'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/sudo-redirection3.zsh b/highlighters/main/test-data/sudo-redirection3.zsh
index 91d456d..fdd426d 100644
--- a/highlighters/main/test-data/sudo-redirection3.zsh
+++ b/highlighters/main/test-data/sudo-redirection3.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[redirection]=$unused_highlight
 BUFFER='sudo 2>./. -u otheruser ls'
 
 expected_region_highlight=(
diff --git a/highlighters/main/test-data/unbackslash.zsh b/highlighters/main/test-data/unbackslash.zsh
index 9731df5..c8dfbd4 100644
--- a/highlighters/main/test-data/unbackslash.zsh
+++ b/highlighters/main/test-data/unbackslash.zsh
@@ -27,7 +27,6 @@
 # vim: ft=zsh sw=2 ts=2 et
 # -------------------------------------------------------------------------------------------------
 
-ZSH_HIGHLIGHT_STYLES[command]=$unused_highlight
 BUFFER='\sh'
 
 expected_region_highlight=(
diff --git a/tests/test-highlighting.zsh b/tests/test-highlighting.zsh
index 83b4b3c..d08237f 100755
--- a/tests/test-highlighting.zsh
+++ b/tests/test-highlighting.zsh
@@ -63,7 +63,6 @@ ZSH_HIGHLIGHT_HIGHLIGHTERS=($1)
 # $1: data file
 run_test_internal() {
   local -a highlight_zone
-  local unused_highlight='bg=red,underline' # a style unused by anything else, for tests to use
 
   local tests_tempdir="$1"; shift
   local srcdir="$PWD"
diff --git a/tests/test-perfs.zsh b/tests/test-perfs.zsh
index 5d94b37..3411754 100755
--- a/tests/test-perfs.zsh
+++ b/tests/test-perfs.zsh
@@ -57,7 +57,6 @@ ZSH_HIGHLIGHT_HIGHLIGHTERS=($1)
 # $1: data file
 run_test_internal() {
   local -a highlight_zone
-  local unused_highlight='bg=red,underline' # a style unused by anything else, for tests to use
 
   local tests_tempdir="$1"; shift
   local srcdir="$PWD"