diff --git a/lib/spectrum.sh b/lib/spectrum.sh
index 450f79e..fc82148 100644
--- a/lib/spectrum.sh
+++ b/lib/spectrum.sh
@@ -3,47 +3,61 @@
 # P.C. Shyamshankar <sykora@lucentbeing.com>
 # Copied from http://github.com/sykora/etc/blob/master/zsh/functions/spectrum/
 
+_omb_module_require lib:omb-deprecate
 _omb_module_require lib:omb-prompt-colors
 
 # typeset in bash does not have associative arrays, declare does in bash 4.0+
 # https://stackoverflow.com/a/6047948
 
-# This library only works for BASH 4.x to keep the minimum compatible for macOS.
+# This library only works for BASH 4.x to keep the minimum compatibility for macOS.
 # shellcheck disable=SC2034
-if [ "${BASH_VERSINFO[0]}" -gt 4 ]; then 
-  _RED='\033[0;31m' # Red Color (For error)
-  _NC='\033[0m' # No Color (To reset the terminal color)
-
-  declare -Ag FX FG BG
-
-  FX=(
-      [reset]="%{^[[00m%}"
-      [bold]="%{^[[01m%}"       [no-bold]="%{^[[22m%}"
-      [italic]="%{^[[03m%}"     [no-italic]="%{^[[23m%}"
-      [underline]="%{^[[04m%}"  [no-underline]="%{^[[24m%}"
-      [blink]="%{^[[05m%}"      [no-blink]="%{^[[25m%}"
-      [reverse]="%{^[[07m%}"    [no-reverse]="%{^[[27m%}"
-  )
-
-  for color in {000..255}; do
-      FG[$color]="%{^[[38;5;${color}m%}"
-      BG[$color]="%{^[[48;5;${color}m%}"
-  done
-
-
-  OSH_SPECTRUM_TEXT=${OSH_SPECTRUM_TEXT:-Arma virumque cano Troiae qui primus ab oris}
-
-  # Show all 256 colors with color number
-  function spectrum_ls() {
-    for code in {000..255}; do
-      print -P -- "$code: %{$FG[$code]%}$OSH_SPECTRUM_TEXT%{$_omb_prompt_reset_color%}"
+if ((_omb_bash_version >= 40000)); then
+  declare -gA _omb_spectrum_fx=()
+  declare -gA _omb_spectrum_fg=()
+  declare -gA _omb_spectrum_bg=()
+  function _omb_spectrum__initialize() {
+    _omb_spectrum_fx=(
+      [reset]=$'\e[00m'
+      [bold]=$'\e[01m'       [no-bold]=$'\e[22m'
+      [italic]=$'\e[03m'     [no-italic]=$'\e[23m'
+      [underline]=$'\e[04m'  [no-underline]=$'\e[24m'
+      [blink]=$'\e[05m'      [no-blink]=$'\e[25m'
+      [reverse]=$'\e[07m'    [no-reverse]=$'\e[27m'
+    )
+    local color
+    for color in {000..255}; do
+      _omb_spectrum_fg[$color]=$'\e[38;5;'${color}'m'
+      _omb_spectrum_bg[$color]=$'\e[48;5;'${color}'m'
     done
   }
+  _omb_spectrum__initialize
 
-  # Show all 256 colors where the background is set to specific color
-  function spectrum_bls() {
-    for code in {000..255}; do
-      print -P -- "$code: %{$BG[$code]%}$OSH_SPECTRUM_TEXT%{$_omb_prompt_reset_color%}"
-    done
+  declare -gA FX FG BG
+  _omb_deprecate_const 20000 _RED "${_omb_term_red}"   "Please use '_omb_term_red'."
+  _omb_deprecate_const 20000 _NC  "${_omb_term_reset}" "Please use '_omb_term_reset'."
+  function _omb_spectrum__deprecate() {
+    local key
+    for key in "${!_omb_spectrum_fx[@]}"; do FX[$key]=${_omb_spectrum_fx[$key]}; done
+    for key in "${!_omb_spectrum_fg[@]}"; do FG[$key]=${_omb_spectrum_fg[$key]}; done
+    for key in "${!_omb_spectrum_bg[@]}"; do BG[$key]=${_omb_spectrum_bg[$key]}; done
   }
+  _omb_spectrum__deprecate
 fi
+
+OSH_SPECTRUM_TEXT=${OSH_SPECTRUM_TEXT:-Arma virumque cano Troiae qui primus ab oris}
+
+# Show all 256 colors with color number
+function spectrum_ls() {
+  local code
+  for code in {000..255}; do
+    printf '%s: \e[38;5;%sm%s%s\n' "$code" "$code" "$OSH_SPECTRUM_TEXT" "$_omb_term_reset"
+  done
+}
+
+# Show all 256 colors where the background is set to specific color
+function spectrum_bls() {
+  local code
+  for code in {000..255}; do
+    printf '%s: \e[48;5;%sm%s%s\n' "$code" "$code" "$OSH_SPECTRUM_TEXT" "$_omb_term_reset"
+  done
+}