qmk layer underglow

void matrix_scan_user(void) {
  #ifdef RGBLIGHT_ENABLE

  static uint8_t old_layer = 255;
  uint8_t new_layer = biton32(layer_state);

  if (old_layer != new_layer) {
    switch (new_layer) {
      case _QWERTY:
        rgblight_sethsv (300,255,255);
        break;
      case _RAISE:
        rgblight_sethsv (184,255,255);
        break;
      case _LOWER:
        rgblight_sethsv (238,255,255);
        break;
      case _ADJUST:
        rgblight_sethsv (0,255,255);
                break;
    }

    old_layer = new_layer;
  }

  #endif //RGBLIGHT_ENABLE
}