fix wallpaper not switching when setting a custom accent color (#2850)

dots/.config/quickshell/ii/scripts/colors/switchwall.sh

@@ -406,6 +406,12 @@ main() {
         imgpath="$(kdialog --getopenfilename . --title 'Choose wallpaper')"
     fi
 
+    if [[ -n "$imgpath" && -z "$noswitch_flag" ]]; then
+        set_accent_color ""
+        color_flag=""
+        color=""
+    fi
+
     # If type_flag is 'auto', detect scheme type from image (after imgpath is set)
     if [[ "$type_flag" == "auto" ]]; then
         if [[ -n "$imgpath" && -f "$imgpath" ]]; then