false case scenario

lib/ansi.bash

@@ -25,7 +25,7 @@ BG_COLORS["BLUE"]='\e[44m'
 BG_COLORS["PURPLE"]='\e[45m'
 BG_COLORS["CYAN"]='\e[46m'
 BG_COLORS["WHITE"]='\e[47m'
-BG_COLORS["GRAY"]='\e[90m'
+# BG_COLORS["GRAY"]='\e[90m'
 # BG_COLORS["MAGENTA"]='\e[95m'
 
 # FUNCTIONS
@@ -55,7 +55,11 @@ function _style_fg {
 }
 
 function _style_bg {
-  [[ -n $1 ]] && echo "${BG_COLORS[$1]}" || true
+  if [[ -n "$1" ]]; then
+    [[ -v BG_COLORS[$1] ]] && echo "${BG_COLORS[$1]}" && return
+    >&2 echo "unknown BG value: $1"
+    false
+  fi
 }
 
 function style_ansi {