Ensure colour consistency between terminal themes

* Comment file for review-ability
* Add BOLD and UNDERLINE options
* Select most readable colours out of LIGHT/DARK options
* Provide empty variables for `set -u`
* Deprecate unnecessary variables
* Correct colours for TICK/CROSS/DONE
* Escape r twice and add ESC to OVER

advanced/Scripts/COL_TABLE

@@ -1,28 +1,49 @@
+# Determine if terminal is capable of showing colours
 if [[ -t 1 ]] && [[ $(tput colors) -ge 8 ]]; then
+  # Bold and underline may not show up on all clients
+  # If something MUST be emphasised, use both
+  COL_BOLD=''
+  COL_ULINE=''
+
   COL_NC=''
-  COL_WHITE=''
-  COL_BLACK=''
-  COL_BLUE=''
-  COL_LIGHT_BLUE=''
-  COL_GREEN=''
-  COL_LIGHT_GREEN=''
-  COL_CYAN=''
-  COL_LIGHT_CYAN=''
-  COL_RED=''
-  COL_LIGHT_RED=''
-  COL_URG_RED=''
-  COL_PURPLE=''
-  COL_LIGHT_PURPLE=''
-  COL_BROWN=''
-  COL_YELLOW=''
-  COL_GRAY=''
-  COL_LIGHT_GRAY=''
-  COL_DARK_GRAY=''
+  COL_GRAY=''
+  COL_RED=''
+  COL_GREEN=''
+  COL_YELLOW=''
+  COL_BLUE=''
+  COL_PURPLE=''
+  COL_CYAN=''
+else
+  # Provide empty variables for `set -u`
+  COL_BOLD=""
+  COL_ULINE=""
+
+  COL_NC=""
+  COL_GRAY=""
+  COL_RED=""
+  COL_GREEN=""
+  COL_YELLOW=""
+  COL_BLUE=""
+  COL_PURPLE=""
+  COL_CYAN=""
 fi
 
-TICK="[${COL_LIGHT_GREEN}✓${COL_NC}]"
-CROSS="[${COL_LIGHT_RED}✗${COL_NC}]"
+# Deprecated variables
+COL_WHITE="${COL_BOLD}"
+COL_BLACK="${COL_NC}"
+COL_LIGHT_BLUE="${COL_BLUE}"
+COL_LIGHT_GREEN="${COL_GREEN}"
+COL_LIGHT_CYAN="${COL_CYAN}"
+COL_LIGHT_RED="${COL_RED}"
+COL_URG_RED="${COL_RED}${COL_BOLD}${COL_ULINE}"
+COL_LIGHT_PURPLE="${COL_PURPLE}"
+COL_BROWN="${COL_YELLOW}"
+COL_LIGHT_GRAY="${COL_GRAY}"
+COL_DARK_GRAY="${COL_GRAY}"
+
+TICK="[${COL_GREEN}✓${COL_NC}]"
+CROSS="[${COL_RED}✗${COL_NC}]"
 INFO="[i]"
 QST="[?]"
-DONE="${COL_LIGHT_GREEN} done!${COL_NC}"
-OVER="\r\033[K"
+DONE="${COL_GREEN} done!${COL_NC}"
+OVER="\\r"