Made custom colors grey-out when the Crazyflie disconnects

Author: ArisMorgens

src/cfclient/ui/tabs/ColorLEDTab.py

@@ -629,7 +629,7 @@ def _add_custom_color_button(self):
             return
 
         new_btn = QPushButton()
-        new_btn.setStyleSheet(f"background-color: {color_hex};")
+        new_btn.setStyleSheet(f"QPushButton {{ background-color: {color_hex}; }} QPushButton:disabled {{ background-color: #777777; }}")
         new_btn.setFixedSize(50, 30)
         new_btn.clicked.connect(self._on_color_button_clicked)
         new_btn.setContextMenuPolicy(Qt.ContextMenuPolicy.CustomContextMenu)