I tried all your examples: python, WindowsQT and a UDP tool.
There is no list of my color bulb.
The yeelight apk from google is closed after a black screen and it only worked once.
How do I talk to the LED bulb using TCP or UDP?
You can’t unless you turn on LAN mode from Yeelight app.
Yes I got it this morning: I turned on Bluetooth and I could start the Yeelight-App. Then I turned on LAN-Control in the menue of the bulb.
Using
Telnet 192.168.178.25:55443 I could connect to the bulb and change its state! GREAT!
You should mention to turn on LAN-CONTROL in the development guide.
Now I create a Heroku-Python-skript for Google Home and I will buy many more of your devices.
Without soldering or firmware flashing! I like it. Better than sonoff!