Hey all! I have this sketch for some ligthing using Home Assistant as controller

Hey all!
I have this sketch for some ligthing using Home Assistant as controller (mysensors 2.0 + fastled), it works great and all, but I was curious if it is possible to blend colors when selecting a new one? Right now when you switch colors/effects it makes a instant change, it would’ve been nice to somehow “blend/fade” between current state and new state/color recieved from Home Assistant, is this even possible looking at the current code I have here or is it a no-go?
http://hastebin.com/ciwizasuhi.coffee

I feel like this is a bit too technical/beyond me right now.
Thanks for any input!