I use an ESP8266 D1 Mini Board, but almost any other ESP8266 or ESP32 controller will work, you just have to change the GPIO numbers.
To control the on/off lines of the warning light I use the outputs D5, D6 and D7 (see firmware).
Connections:
Controller | Light |
D5 | Yellow on/off |
D6 | Green on/off |
D7 | Red on/off |
GND | black cable (minus) |