The RGB Serial WS2812 Processing interface allow to control a single or a strip of leds RGB WS2812 from a serial comunication:
At the start of the Processing software you're going to show this start image:
When you're going to move each color bar the value of the color change and it's going to send to Arduino sketch.
The project is available on the arduino one board (and on all the other boards of the arduino family)
The project is available on the ESP8266 only changing the board in the Arduino IDE -> Menu Tools -> Boards -> Wemos D1 Mini
You can see the video of the experiment on my Youtube Channel