It would depend on the technology being used to control the color changing. A very small handful of VERY expensive RGBW lighting systems utilize a communication wire added to the run to talk to the lights and make them change color. A more common, and newer technology is to utilize secure BT networks to create the mesh and changing of colors. Other, less expensive options utilize wifi to talk to the string of lights (think Govee or Hue, but those aren’t usually expandible, and utilize their own apps to make changes.
All that to be said, the Rachio unit itself is a basic lighting transformer at the core, with a pretty cool cloud based UI. It can dim the lights by adjusting the voltage out of the unit, but cannot control color changing.