komorebi/docs/common-workflows/active-window-border.md

Active Window Border

If you would like to add a visual border around the currently focused window, ensure the following options are defined in the komorebi.json configuration file.

{
  "active_window_border": true,
  "active_window_border_style": "Rounded",
  "active_window_border_colours": {
    "single": {
      "r": 66,
      "g": 165,
      "b": 245
    },
    "stack": {
      "r": 256,
      "g": 165,
      "b": 66
    },
    "monocle": {
      "r": 255,
      "g": 51,
      "b": 153
    }
  },
}

It is important to note that the active window border will only apply to windows managed by komorebi.

This feature is not considered stable, and you may encounter visual artifacts from time to time.