我的LinearLayout有这个背景图片： Background image
我有这个可绘制的：
Traceback (most recent call last):
File "command3.py", line 47, in <module>
microgear.connect(True)
File "/usr/local/lib/python2.7/dist-packages/microgear/client.py", line 143, in connect
microgear.mqtt_client.loop_forever()
File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", line 1378, in loop_forever
rc = self.loop(timeout, max_packets)
File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", line 897, in loop
rc = self.loop_read(max_packets)
File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", line 1177, in loop_read
rc = self._packet_read()
File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", line 1766, in _packet_read
rc = self._packet_handle()
File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", line 2239, in _packet_handle
return self._handle_publish()
File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", line 2414, in _handle_publish
self._handle_on_message(message)
File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", line 2574, in _handle_on_message
self.on_message(self, self._userdata, message)
File "/usr/local/lib/python2.7/dist-packages/microgear/client.py", line 105, in client_on_message
on_message(msg.topic,str(msg.payload))
File "command3.py", line 35, in subscription
proc.terminate()
UnboundLocalError: local variable 'proc' referenced before assignment
而不是COLOR1，COLOR2，color3，我可以使用哪种颜色与背景颜色形成最佳对比。