use BT logo for devices

libs/devices/devices.cpp

@@ -123,7 +123,7 @@ enum class MesDpadButtonInfo {
 /**
  * Control a phone with the BBC micro:bit via Bluetooth.
  */
-//% color=156 weight=80
+//% color=#008272 weight=80 icon="\uf10b"
 namespace devices {
     static void genEvent(int id, int event) {
       MicroBitEvent e(id, event);