WS2812FX
WS2812 FX library for Arduino and ESP8266
...You can search for WS2812FX in the Arduino IDE Library Manager or install the latest (or development) version manually. More complex effects can be created by dividing your string of LEDs into segments (up to ten) and programming each segment independently. Use the segment() function to program each segment's mode, color, speed, and direction (normal or reverse). Note, some effects make use of more than one color (up to three) and are programmed by specifying an array of colors. Random color introduced alternating from start and end of strip. Alternating white/red/black pixels running. ...