Update

local/share/sway/scripts/wob.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env sh
+# https://github.com/francma/wob/wiki/wob-wrapper-script
+#$1 - accent color. $2 - background color. $3 - new value
+# returns 0 (success) if $1 is running and is attached to this sway session; else 1
+is_running_on_this_screen() {
+    pkill -U $USER -x -0 "wob" || return 1
+    for pid in $(pgrep "wob"); do
+        WOB_SWAYSOCK="$(tr '\0' '\n' </proc/"$pid"/environ | awk -F'=' '/^SWAYSOCK/ {print $2}')"
+        if [ "$WOB_SWAYSOCK" = "$SWAYSOCK" ]; then
+            return 0
+        fi
+    done
+    return 1
+}
+
+wob_pipe=~/.cache/$(basename "$SWAYSOCK").wob
+
+[ -p "$wob_pipe" ] || mkfifo "$wob_pipe"
+
+ini=~/.config/wob.ini
+
+refresh() {
+    pkill -U $USER -x wob
+    rm $ini
+    {
+        echo "anchor = top center"
+        echo "margin = 20"
+        echo "border_color = $(echo "$1" | sed 's/#//')"
+        echo "bar_color = $(echo "$1" | sed 's/#//')"
+        echo "background_color = $(echo "$2" | sed 's/#//')"
+    } >>$ini
+}
+
+if [ ! -f "$ini" ] || [ "$3" = "--refresh" ]; then
+   refresh "$1" "$2"
+fi
+
+# wob does not appear in $(swaymsg -t get_msg), so:
+is_running_on_this_screen || {
+    tail -f "$wob_pipe" | wob -c $ini &
+}
+
+if [ "$3" = "--refresh" ]; then
+    exit 0;
+elif [ -n "$3" ]; then
+    echo "$3" >"$wob_pipe"
+else
+    cat >"$wob_pipe"
+fi